diff --git a/sqlglot/dialects/bigquery.py b/sqlglot/dialects/bigquery.py
index 228440f360..1a886546ad 100644
--- a/sqlglot/dialects/bigquery.py
+++ b/sqlglot/dialects/bigquery.py
@@ -269,6 +269,8 @@ class Generator(generator.Generator):
             exp.DataType.Type.NVARCHAR: "STRING",
             exp.DataType.Type.SMALLINT: "INT64",
             exp.DataType.Type.TEXT: "STRING",
+            exp.DataType.Type.TIMESTAMP: "DATETIME",
+            exp.DataType.Type.TIMESTAMPTZ: "TIMESTAMP",
             exp.DataType.Type.TINYINT: "INT64",
             exp.DataType.Type.VARCHAR: "STRING",
             exp.DataType.Type.VARIANT: "ANY TYPE",
diff --git a/tests/dialects/test_bigquery.py b/tests/dialects/test_bigquery.py
index 6792df0f30..703b7dc0a1 100644
--- a/tests/dialects/test_bigquery.py
+++ b/tests/dialects/test_bigquery.py
@@ -22,6 +22,8 @@ def test_bigquery(self):
         self.validate_all("CAST(x AS CHAR)", write={"bigquery": "CAST(x AS STRING)"})
         self.validate_all("CAST(x AS NCHAR)", write={"bigquery": "CAST(x AS STRING)"})
         self.validate_all("CAST(x AS NVARCHAR)", write={"bigquery": "CAST(x AS STRING)"})
+        self.validate_all("CAST(x AS TIMESTAMP)", write={"bigquery": "CAST(x AS DATETIME)"})
+        self.validate_all("CAST(x AS TIMESTAMPTZ)", write={"bigquery": "CAST(x AS TIMESTAMP)"})
         self.validate_all(
             "SELECT ARRAY(SELECT AS STRUCT 1 a, 2 b)",
             write={
diff --git a/tests/dialects/test_duckdb.py b/tests/dialects/test_duckdb.py
index 7100dec436..9e0040ca11 100644
--- a/tests/dialects/test_duckdb.py
+++ b/tests/dialects/test_duckdb.py
@@ -80,7 +80,7 @@ def test_time(self):
                 "snowflake": "CONVERT_TIMEZONE('America/New_York', CAST(start AS TIMESTAMPTZ))",
             },
             write={
-                "bigquery": "TIMESTAMP(DATETIME(CAST(start AS TIMESTAMPTZ), 'America/New_York'))",
+                "bigquery": "TIMESTAMP(DATETIME(CAST(start AS TIMESTAMP), 'America/New_York'))",
                 "duckdb": "CAST(start AS TIMESTAMPTZ) AT TIME ZONE 'America/New_York'",
                 "snowflake": "CONVERT_TIMEZONE('America/New_York', CAST(start AS TIMESTAMPTZ))",
             },
diff --git a/tests/dialects/test_presto.py b/tests/dialects/test_presto.py
index 3d4ea7f13a..30804768d9 100644
--- a/tests/dialects/test_presto.py
+++ b/tests/dialects/test_presto.py
@@ -60,7 +60,7 @@ def test_cast(self):
         self.validate_all(
             "CAST(x AS TIMESTAMP(9) WITH TIME ZONE)",
             write={
-                "bigquery": "CAST(x AS TIMESTAMPTZ)",
+                "bigquery": "CAST(x AS TIMESTAMP)",
                 "duckdb": "CAST(x AS TIMESTAMPTZ(9))",
                 "presto": "CAST(x AS TIMESTAMP(9) WITH TIME ZONE)",
                 "hive": "CAST(x AS TIMESTAMP)",