diff --git a/ibis/backends/tests/test_generic.py b/ibis/backends/tests/test_generic.py
index f0b82b43680f..c508b696666f 100644
--- a/ibis/backends/tests/test_generic.py
+++ b/ibis/backends/tests/test_generic.py
@@ -947,6 +947,39 @@ def test_memtable_construct(backend, con, monkeypatch):
     )
 
 
+@pytest.mark.parametrize(
+    "df, columns, expected",
+    [
+        (pd.DataFrame([("a", 1.0)], columns=["d", "f"]), ["a", "b"], ["a", "b"]),
+        (pd.DataFrame([("a", 1.0)]), ["A", "B"], ["A", "B"]),
+        (pd.DataFrame([("a", 1.0)], columns=["c", "d"]), None, ["c", "d"]),
+        ([("a", "1.0")], None, ["col0", "col1"]),
+        ([("a", "1.0")], ["d", "e"], ["d", "e"]),
+    ],
+)
+def test_memtable_column_naming(backend, con, monkeypatch, df, columns, expected):
+    monkeypatch.setattr(ibis.options, "default_backend", con)
+
+    t = ibis.memtable(df, columns=columns)
+    assert all(t.to_pandas().columns == expected)
+
+
+@pytest.mark.parametrize(
+    "df, columns",
+    [
+        (pd.DataFrame([("a", 1.0)], columns=["d", "f"]), ["a"]),
+        (pd.DataFrame([("a", 1.0)]), ["A", "B", "C"]),
+        ([("a", "1.0")], ["col0", "col1", "col2"]),
+        ([("a", "1.0")], ["d"]),
+    ],
+)
+def test_memtable_column_naming_mismatch(backend, con, monkeypatch, df, columns):
+    monkeypatch.setattr(ibis.options, "default_backend", con)
+
+    with pytest.raises(ValueError):
+        ibis.memtable(df, columns=columns)
+
+
 @pytest.mark.notimpl(
     ["dask", "datafusion", "pandas", "polars"],
     raises=NotImplementedError,
diff --git a/ibis/expr/api.py b/ibis/expr/api.py
index f993667ab76b..5bd3e04e997c 100644
--- a/ibis/expr/api.py
+++ b/ibis/expr/api.py
@@ -371,7 +371,8 @@ def memtable(
         Do not depend on the underlying storage type (e.g., pyarrow.Table), it's subject
         to change across non-major releases.
     columns
-        Optional [](`typing.Iterable`) of [](`str`) column names.
+        Optional [](`typing.Iterable`) of [](`str`) column names. If provided,
+        must match the number of columns in `data`.
     schema
         Optional [`Schema`](./schemas.qmd#ibis.expr.schema.Schema).
         The functions use `data` to infer a schema if not passed.
@@ -468,7 +469,11 @@ def _memtable_from_dataframe(
 
     from ibis.expr.operations.relations import PandasDataFrameProxy
 
-    df = pd.DataFrame(data, columns=columns)
+    if not isinstance(data, pd.DataFrame):
+        df = pd.DataFrame(data, columns=columns)
+    else:
+        df = data
+
     if df.columns.inferred_type != "string":
         cols = df.columns
         newcols = getattr(
@@ -478,6 +483,15 @@ def _memtable_from_dataframe(
         )
         df = df.rename(columns=dict(zip(cols, newcols)))
 
+    if columns is not None:
+        if (provided_col := len(columns)) != (exist_col := len(df.columns)):
+            raise ValueError(
+                "Provided `columns` must have an entry for each column in `data`.\n"
+                f"`columns` has {provided_col} elements but `data` has {exist_col} columns."
+            )
+
+        df = df.rename(columns=dict(zip(df.columns, columns)))
+
     # verify that the DataFrame has no duplicate column names because ibis
     # doesn't allow that
     cols = df.columns