diff --git a/CHANGELOG.md b/CHANGELOG.md
index 149ea8d8bc7..3fa07b2d99c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 
 - We added support for searching ShortScience for an entry through the user's browser. [#6018](https://github.com/JabRef/jabref/pull/6018)
 - We added tooltips for most fields in the entry editor containing a short description. [#5847](https://github.com/JabRef/jabref/issues/5847)
+- We added support for basic markdown in custom formatted previews [#6194](https://github.com/JabRef/jabref/issues/6194)
 
 ### Changed
 
diff --git a/build.gradle b/build.gradle
index b0953b82aae..48afce41006 100644
--- a/build.gradle
+++ b/build.gradle
@@ -195,6 +195,7 @@ dependencies {
         exclude module: "log4j-core"
     }
 
+    implementation 'com.vladsch.flexmark:flexmark-all:0.60.2'
 
     testImplementation 'io.github.classgraph:classgraph:4.8.65'
     testImplementation 'org.junit.jupiter:junit-jupiter:5.6.1'
diff --git a/external-libraries.txt b/external-libraries.txt
index f67e09af7fd..05e11258f7d 100644
--- a/external-libraries.txt
+++ b/external-libraries.txt
@@ -334,6 +334,11 @@ Project: OpenOffice.org
 URL:     http://www.openoffice.org/api/SDK
 License: Apache-2.0
 
+Id:      com.vladsch.flexmark:flexmark-all
+Project: flexmark-java
+URL:     https://github.com/vsch/flexmark-java
+License: BSD-2-Clause
+
 ## Sorted list of runtime dependencies output by gradle
 
 ```text
diff --git a/src/main/java/module-info.java b/src/main/java/module-info.java
index 91b721e8a4a..d04c03e13f2 100644
--- a/src/main/java/module-info.java
+++ b/src/main/java/module-info.java
@@ -82,4 +82,11 @@
     requires org.antlr.antlr4.runtime;
     requires flowless;
     requires org.apache.tika.core;
+
+    requires flexmark;
+    requires flexmark.ext.gfm.strikethrough;
+    requires flexmark.ext.gfm.tasklist;
+    requires flexmark.util.ast;
+    requires flexmark.util.data;
+    requires annotations;
 }
diff --git a/src/main/java/org/jabref/logic/layout/LayoutEntry.java b/src/main/java/org/jabref/logic/layout/LayoutEntry.java
index ec7d6067a7e..ee6632a7046 100644
--- a/src/main/java/org/jabref/logic/layout/LayoutEntry.java
+++ b/src/main/java/org/jabref/logic/layout/LayoutEntry.java
@@ -57,6 +57,7 @@
 import org.jabref.logic.layout.format.JournalAbbreviator;
 import org.jabref.logic.layout.format.LastPage;
 import org.jabref.logic.layout.format.LatexToUnicodeFormatter;
+import org.jabref.logic.layout.format.MarkdownFormatter;
 import org.jabref.logic.layout.format.NameFormatter;
 import org.jabref.logic.layout.format.NoSpaceBetweenAbbreviations;
 import org.jabref.logic.layout.format.NotFoundFormatter;
@@ -536,6 +537,8 @@ private LayoutFormatter getLayoutFormatterByName(String name) {
                 return new WrapContent();
             case "WrapFileLinks":
                 return new WrapFileLinks(prefs.getFileLinkPreferences());
+            case "Markdown":
+                return new MarkdownFormatter();
             default:
                 return null;
         }
diff --git a/src/main/java/org/jabref/logic/layout/format/MarkdownFormatter.java b/src/main/java/org/jabref/logic/layout/format/MarkdownFormatter.java
new file mode 100644
index 00000000000..4aeff2a55ad
--- /dev/null
+++ b/src/main/java/org/jabref/logic/layout/format/MarkdownFormatter.java
@@ -0,0 +1,42 @@
+package org.jabref.logic.layout.format;
+
+import java.util.List;
+import java.util.Objects;
+
+import org.jabref.logic.layout.LayoutFormatter;
+
+import com.vladsch.flexmark.ext.gfm.strikethrough.StrikethroughExtension;
+import com.vladsch.flexmark.ext.gfm.tasklist.TaskListExtension;
+import com.vladsch.flexmark.html.HtmlRenderer;
+import com.vladsch.flexmark.parser.Parser;
+import com.vladsch.flexmark.util.ast.Node;
+import com.vladsch.flexmark.util.data.MutableDataSet;
+
+public class MarkdownFormatter implements LayoutFormatter {
+
+    private final Parser parser;
+    private final HtmlRenderer renderer;
+
+    public MarkdownFormatter() {
+        MutableDataSet options = new MutableDataSet();
+        options.set(Parser.EXTENSIONS, List.of(
+                StrikethroughExtension.create(),
+                TaskListExtension.create()
+        ));
+        options.set(HtmlRenderer.NO_P_TAGS_USE_BR, true);
+
+        parser = Parser.builder(options).build();
+        renderer = HtmlRenderer.builder(options).build();
+    }
+
+    @Override
+    public String format(final String fieldText) {
+        Objects.requireNonNull(fieldText, "Field Text should not be null, when handed to formatter");
+
+        Node document = parser.parse(fieldText);
+        String html = renderer.render(document);
+
+        // workaround HTMLChars transforming "\n" into <br> by returning a one liner
+        return html.replaceAll("\\r\\n|\\r|\\n", " ").trim();
+    }
+}
diff --git a/src/main/java/org/jabref/migrations/PreferencesMigrations.java b/src/main/java/org/jabref/migrations/PreferencesMigrations.java
index d841a6c0c08..d1fcd36b57a 100644
--- a/src/main/java/org/jabref/migrations/PreferencesMigrations.java
+++ b/src/main/java/org/jabref/migrations/PreferencesMigrations.java
@@ -49,6 +49,7 @@ public static void runMigrations() {
         addCrossRefRelatedFieldsForAutoComplete(Globals.prefs);
         upgradePreviewStyleFromReviewToComment(Globals.prefs);
         upgradeColumnPreferences(Globals.prefs);
+        upgradePreviewStyleAllowMarkdown(Globals.prefs);
     }
 
     /**
@@ -301,6 +302,12 @@ static void upgradePreviewStyleFromReviewToComment(JabRefPreferences prefs) {
         prefs.setPreviewStyle(migratedStyle);
     }
 
+    static void upgradePreviewStyleAllowMarkdown(JabRefPreferences prefs) {
+        String currentPreviewStyle = prefs.getPreviewStyle();
+        String migratedStyle = currentPreviewStyle.replace("\\begin{comment}<BR><BR><b>Comment: </b> \\format[HTMLChars]{\\comment} \\end{comment}", "\\begin{comment}<BR><BR><b>Comment: </b> \\format[Markdown,HTMLChars]{\\comment} \\end{comment}");
+        prefs.setPreviewStyle(migratedStyle);
+    }
+
     /**
      * The former preferences default of columns was a simple list of strings ("author;title;year;..."). Since 5.0
      * the preferences store the type of the column too, so that the formerly hardwired columns like the graphic groups
diff --git a/src/main/java/org/jabref/preferences/JabRefPreferences.java b/src/main/java/org/jabref/preferences/JabRefPreferences.java
index 096396915f3..5dddcd3b233 100644
--- a/src/main/java/org/jabref/preferences/JabRefPreferences.java
+++ b/src/main/java/org/jabref/preferences/JabRefPreferences.java
@@ -674,7 +674,7 @@ private JabRefPreferences() {
                                     + "\\begin{year}<b>\\year</b>\\end{year}\\begin{volume}<i>, \\volume</i>\\end{volume}"
                                     + "\\begin{pages}, \\format[FormatPagesForHTML]{\\pages} \\end{pages}__NEWLINE__"
                                     + "\\begin{abstract}<BR><BR><b>Abstract: </b> \\format[HTMLChars]{\\abstract} \\end{abstract}__NEWLINE__"
-                                    + "\\begin{comment}<BR><BR><b>Comment: </b> \\format[HTMLChars]{\\comment} \\end{comment}"
+                                    + "\\begin{comment}<BR><BR><b>Comment: </b> \\format[Markdown,HTMLChars]{\\comment} \\end{comment}"
                                     + "</dd>__NEWLINE__<p></p></font>");
 
         // set default theme
diff --git a/src/test/java/org/jabref/logic/layout/format/MarkdownFormatterTest.java b/src/test/java/org/jabref/logic/layout/format/MarkdownFormatterTest.java
new file mode 100644
index 00000000000..a09bfe97c65
--- /dev/null
+++ b/src/test/java/org/jabref/logic/layout/format/MarkdownFormatterTest.java
@@ -0,0 +1,60 @@
+package org.jabref.logic.layout.format;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+class MarkdownFormatterTest {
+
+    private MarkdownFormatter markdownFormatter;
+
+    @BeforeEach
+    void setUp() {
+        markdownFormatter = new MarkdownFormatter();
+    }
+
+    @Test
+    void formatWhenFormattingPlainTextThenReturnsTextWrappedInParagraph() {
+        assertThat(markdownFormatter.format("Hello World")).isEqualTo("<p>Hello World</p>");
+    }
+
+    @Test
+    void formatWhenFormattingComplexMarkupThenReturnsOnlyOneLine() {
+        String source = "Markup\n\n* list item one\n* list item 2\n\n rest";
+        assertThat(markdownFormatter.format(source))
+                .contains("Markup<br />")
+                .contains("<li>list item one</li>")
+                .contains("<li>list item 2</li>")
+                .contains("> rest")
+                .doesNotContain("\n");
+    }
+
+    @Test
+    void formatWhenFormattingEmptyStringThenReturnsEmptyString() {
+        assertThat(markdownFormatter.format("")).isEqualTo("");
+    }
+
+    @Test
+    void formatWhenFormattingNullThenThrowsException() {
+        assertThatExceptionOfType(NullPointerException.class).isThrownBy(() -> markdownFormatter.format(null))
+                                                             .withMessageContaining("Field Text should not be null, when handed to formatter")
+                                                             .withNoCause();
+    }
+
+    @Test
+    void formatWhenMarkupContainingStrikethroughThenContainsMatchingDel() {
+        assertThat(markdownFormatter.format("a ~~b~~ b")).contains("<del>b</del>");
+    }
+
+    @Test
+    void formatWhenMarkupContainingTaskListThenContainsFormattedTaskList() {
+        assertThat(markdownFormatter.format("Some text\n" +
+                "* [ ] open task\n" +
+                "* [x] closed task\n\n" +
+                "some other text"))
+                .contains("<li class=\"task-list-item\"><input type=\"checkbox\" class=\"task-list-item-checkbox\" disabled=\"disabled\" readonly=\"readonly\" />&nbsp;open task</li>")
+                .contains("<li class=\"task-list-item\"><input type=\"checkbox\" class=\"task-list-item-checkbox\" checked=\"checked\" disabled=\"disabled\" readonly=\"readonly\" />&nbsp;closed task</li>");
+    }
+}
diff --git a/src/test/java/org/jabref/migrations/PreferencesMigrationsTest.java b/src/test/java/org/jabref/migrations/PreferencesMigrationsTest.java
index 950dc132d47..4ec51549da8 100644
--- a/src/test/java/org/jabref/migrations/PreferencesMigrationsTest.java
+++ b/src/test/java/org/jabref/migrations/PreferencesMigrationsTest.java
@@ -22,7 +22,7 @@ class PreferencesMigrationsTest {
     private final String[] oldStylePatterns = new String[]{"\\bibtexkey",
             "\\bibtexkey\\begin{title} - \\format[RemoveBrackets]{\\title}\\end{title}"};
     private final String[] newStylePatterns = new String[]{"[bibtexkey]",
-                                                            "[bibtexkey] - [title]"};
+            "[bibtexkey] - [title]"};
 
     @BeforeEach
     void setUp() {
@@ -118,6 +118,56 @@ void testPreviewStyle() {
         verify(prefs).setPreviewStyle(newPreviewStyle);
     }
 
+    @Test
+    void upgradePreviewStyleAllowMarkup() {
+        String oldPreviewStyle = "<font face=\"sans-serif\">"
+                + "<b><i>\\bibtextype</i><a name=\"\\bibtexkey\">\\begin{bibtexkey} (\\bibtexkey)</a>"
+                + "\\end{bibtexkey}</b><br>__NEWLINE__"
+                + "\\begin{author} \\format[Authors(LastFirst,Initials,Semicolon,Amp),HTMLChars]{\\author}<BR>\\end{author}__NEWLINE__"
+                + "\\begin{editor} \\format[Authors(LastFirst,Initials,Semicolon,Amp),HTMLChars]{\\editor} "
+                + "<i>(\\format[IfPlural(Eds.,Ed.)]{\\editor})</i><BR>\\end{editor}__NEWLINE__"
+                + "\\begin{title} \\format[HTMLChars]{\\title} \\end{title}<BR>__NEWLINE__"
+                + "\\begin{chapter} \\format[HTMLChars]{\\chapter}<BR>\\end{chapter}__NEWLINE__"
+                + "\\begin{journal} <em>\\format[HTMLChars]{\\journal}, </em>\\end{journal}__NEWLINE__"
+                // Include the booktitle field for @inproceedings, @proceedings, etc.
+                + "\\begin{booktitle} <em>\\format[HTMLChars]{\\booktitle}, </em>\\end{booktitle}__NEWLINE__"
+                + "\\begin{school} <em>\\format[HTMLChars]{\\school}, </em>\\end{school}__NEWLINE__"
+                + "\\begin{institution} <em>\\format[HTMLChars]{\\institution}, </em>\\end{institution}__NEWLINE__"
+                + "\\begin{publisher} <em>\\format[HTMLChars]{\\publisher}, </em>\\end{publisher}__NEWLINE__"
+                + "\\begin{year}<b>\\year</b>\\end{year}\\begin{volume}<i>, \\volume</i>\\end{volume}"
+                + "\\begin{pages}, \\format[FormatPagesForHTML]{\\pages} \\end{pages}__NEWLINE__"
+                + "\\begin{abstract}<BR><BR><b>Abstract: </b> \\format[HTMLChars]{\\abstract} \\end{abstract}__NEWLINE__"
+                + "\\begin{comment}<BR><BR><b>Comment: </b> \\format[HTMLChars]{\\comment} \\end{comment}"
+                + "</dd>__NEWLINE__<p></p></font>";
+
+        String newPreviewStyle = "<font face=\"sans-serif\">"
+                + "<b><i>\\bibtextype</i><a name=\"\\bibtexkey\">\\begin{bibtexkey} (\\bibtexkey)</a>"
+                + "\\end{bibtexkey}</b><br>__NEWLINE__"
+                + "\\begin{author} \\format[Authors(LastFirst,Initials,Semicolon,Amp),HTMLChars]{\\author}<BR>\\end{author}__NEWLINE__"
+                + "\\begin{editor} \\format[Authors(LastFirst,Initials,Semicolon,Amp),HTMLChars]{\\editor} "
+                + "<i>(\\format[IfPlural(Eds.,Ed.)]{\\editor})</i><BR>\\end{editor}__NEWLINE__"
+                + "\\begin{title} \\format[HTMLChars]{\\title} \\end{title}<BR>__NEWLINE__"
+                + "\\begin{chapter} \\format[HTMLChars]{\\chapter}<BR>\\end{chapter}__NEWLINE__"
+                + "\\begin{journal} <em>\\format[HTMLChars]{\\journal}, </em>\\end{journal}__NEWLINE__"
+                // Include the booktitle field for @inproceedings, @proceedings, etc.
+                + "\\begin{booktitle} <em>\\format[HTMLChars]{\\booktitle}, </em>\\end{booktitle}__NEWLINE__"
+                + "\\begin{school} <em>\\format[HTMLChars]{\\school}, </em>\\end{school}__NEWLINE__"
+                + "\\begin{institution} <em>\\format[HTMLChars]{\\institution}, </em>\\end{institution}__NEWLINE__"
+                + "\\begin{publisher} <em>\\format[HTMLChars]{\\publisher}, </em>\\end{publisher}__NEWLINE__"
+                + "\\begin{year}<b>\\year</b>\\end{year}\\begin{volume}<i>, \\volume</i>\\end{volume}"
+                + "\\begin{pages}, \\format[FormatPagesForHTML]{\\pages} \\end{pages}__NEWLINE__"
+                + "\\begin{abstract}<BR><BR><b>Abstract: </b> \\format[HTMLChars]{\\abstract} \\end{abstract}__NEWLINE__"
+                + "\\begin{comment}<BR><BR><b>Comment: </b> \\format[Markdown,HTMLChars]{\\comment} \\end{comment}"
+                + "</dd>__NEWLINE__<p></p></font>";
+
+        prefs.setPreviewStyle(oldPreviewStyle);
+        when(prefs.getPreviewStyle()).thenReturn(oldPreviewStyle);
+
+        PreferencesMigrations.upgradePreviewStyleAllowMarkdown(prefs);
+
+        verify(prefs).setPreviewStyle(newPreviewStyle);
+    }
+
     @Test
     void testUpgradeColumnPreferencesAlreadyMigrated() {
         List<String> columnNames = Arrays.asList("entrytype", "author/editor", "title", "year", "journal/booktitle", "bibtexkey", "printed");
@@ -138,7 +188,7 @@ void testUpgradeColumnPreferencesFromWithoutTypes() {
         List<String> columnWidths = Arrays.asList("75", "300", "470", "60", "130", "100", "30");
         List<String> updatedNames = Arrays.asList("groups", "files", "linked_id", "field:entrytype", "field:author/editor", "field:title", "field:year", "field:journal/booktitle", "field:bibtexkey", "special:printed");
         List<String> updatedWidths = Arrays.asList("28", "28", "28", "75", "300", "470", "60", "130", "100", "30");
-        List<String> newSortTypes = Arrays.asList("ASCENDING","ASCENDING","ASCENDING","ASCENDING","ASCENDING","ASCENDING","ASCENDING","ASCENDING","ASCENDING","ASCENDING");
+        List<String> newSortTypes = Arrays.asList("ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING", "ASCENDING");
 
         when(prefs.getStringList(JabRefPreferences.COLUMN_NAMES)).thenReturn(columnNames);
         when(prefs.getStringList(JabRefPreferences.COLUMN_WIDTHS)).thenReturn(columnWidths);