diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeOnlyConverter.cs b/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeOnlyConverter.cs
index bd2c40c8a07ca..82fc1ad6ac952 100644
--- a/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeOnlyConverter.cs
+++ b/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/TimeOnlyConverter.cs
@@ -10,7 +10,7 @@ namespace System.Text.Json.Serialization.Converters
 {
     internal sealed class TimeOnlyConverter : JsonPrimitiveConverter<TimeOnly>
     {
-        private const int MinimumTimeOnlyFormatLength = 8; // hh:mm:ss
+        private const int MinimumTimeOnlyFormatLength = 3; // h:m
         private const int MaximumTimeOnlyFormatLength = 16; // hh:mm:ss.fffffff
         private const int MaximumEscapedTimeOnlyFormatLength = JsonConstants.MaxExpansionFactorWhileEscaping * MaximumTimeOnlyFormatLength;
 
diff --git a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Value.ReadTests.cs b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Value.ReadTests.cs
index 95a2cde389cf0..9d797c465b716 100644
--- a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Value.ReadTests.cs
+++ b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/Value.ReadTests.cs
@@ -488,6 +488,11 @@ private static void DeserializeLongJsonString(int stringLength)
         }
 
         [Theory]
+        [InlineData("1:2")]
+        [InlineData("01:2")]
+        [InlineData("1:02")]
+        [InlineData("01:23:1")]
+        [InlineData("1.1:1:1.0")]
         [InlineData("1:00:00")]
         [InlineData("1")]
         [InlineData("10")]
@@ -654,6 +659,12 @@ public static void DateOnly_Read_Failure(string json, bool addQuotes = true)
         }
 
         [Theory]
+        [InlineData("1:2", "01:02")]
+        [InlineData("01:2", "01:02")]
+        [InlineData("01:23:1", "01:23:01")]
+        [InlineData("1:00:00")] // 'g' Format
+        [InlineData("00:00")]
+        [InlineData("23:59")]
         [InlineData("23:59:59")]
         [InlineData("23:59:59.9", "23:59:59.9000000")]
         [InlineData("02:48:05.4775807")]
@@ -680,8 +691,9 @@ public static void TimeOnly_Read_Nullable_Tests()
         }
 
         [Theory]
-        [InlineData("00:00")]
-        [InlineData("23:59")]
+        [InlineData("0")]
+        [InlineData("01")]
+        [InlineData("01:")]
         [InlineData("\t23:59:59")] // Otherwise valid but has invalid json character
         [InlineData("\\t23:59:59")] // Otherwise valid but has leading whitespace
         [InlineData("23:59:59   ")] // Otherwise valid but has trailing whitespace
@@ -693,7 +705,6 @@ public static void TimeOnly_Read_Nullable_Tests()
         [InlineData("900000000.00:00:00")]
         [InlineData("1.00:00:00")]
         [InlineData("0.00:00:00")]
-        [InlineData("1:00:00")] // 'g' Format
         [InlineData("1:2:00:00")] // 'g' Format
         [InlineData("+00:00:00")]
         [InlineData("2021-06-18")]