diff --git a/diesel/src/pg/expression/expression_methods.rs b/diesel/src/pg/expression/expression_methods.rs
index f7836c682235..ce1664543cb6 100644
--- a/diesel/src/pg/expression/expression_methods.rs
+++ b/diesel/src/pg/expression/expression_methods.rs
@@ -1,10 +1,10 @@
 //! PostgreSQL specific expression methods
 
 pub(in crate::pg) use self::private::{
-    ArrayOrNullableArray, InetOrCidr, JsonIndex, JsonOrNullableJsonOrJsonbOrNullableJsonb,
-    JsonRemoveIndex, JsonbOrNullableJsonb, MaybeNullableValue, MultirangeOrNullableMultirange,
-    MultirangeOrRangeMaybeNullable, RangeHelper, RangeOrNullableRange,
-    TextArrayOrNullableTextArray, TextOrNullableText,
+    ArrayOrNullableArray, InetOrCidr, JsonIndex, JsonOrNullableJson,
+    JsonOrNullableJsonOrJsonbOrNullableJsonb, JsonRemoveIndex, JsonbOrNullableJsonb,
+    MaybeNullableValue, MultirangeOrNullableMultirange, MultirangeOrRangeMaybeNullable,
+    RangeHelper, RangeOrNullableRange, TextArrayOrNullableTextArray, TextOrNullableText,
 };
 use super::date_and_time::{AtTimeZone, DateTimeLike};
 use super::operators::*;
@@ -3552,6 +3552,11 @@ pub(in crate::pg) mod private {
     impl JsonbOrNullableJsonb for Jsonb {}
     impl JsonbOrNullableJsonb for Nullable<Jsonb> {}
 
+    pub trait JsonOrNullableJson {}
+
+    impl JsonOrNullableJson for Json {}
+    impl JsonOrNullableJson for Nullable<Json> {}
+
     /// A trait that describes valid json indices used by postgresql
     pub trait JsonRemoveIndex {
         /// The Expression node created by this index type
diff --git a/diesel/src/pg/expression/functions.rs b/diesel/src/pg/expression/functions.rs
index bc851a5258e5..6039b02995a2 100644
--- a/diesel/src/pg/expression/functions.rs
+++ b/diesel/src/pg/expression/functions.rs
@@ -3,6 +3,8 @@
 use super::expression_methods::InetOrCidr;
 use crate::expression::functions::define_sql_function;
 use crate::pg::expression::expression_methods::ArrayOrNullableArray;
+use crate::pg::expression::expression_methods::JsonOrNullableJson;
+use crate::pg::expression::expression_methods::JsonbOrNullableJsonb;
 use crate::pg::expression::expression_methods::MaybeNullableValue;
 use crate::pg::expression::expression_methods::MultirangeOrNullableMultirange;
 use crate::pg::expression::expression_methods::MultirangeOrRangeMaybeNullable;
@@ -1634,3 +1636,123 @@ define_sql_function! {
         text_array: Arr,
     ) -> Arr::Out;
 }
+
+#[cfg(feature = "postgres_backend")]
+define_sql_function! {
+    /// Returns the type of the top-level json value as a text-string
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// # include!("../../doctest_setup.rs");
+    /// #
+    /// # fn main() {
+    /// #     #[cfg(feature = "serde_json")]
+    /// #     run_test().unwrap();
+    /// # }
+    /// #
+    /// # #[cfg(feature = "serde_json")]
+    /// # fn run_test() -> QueryResult<()> {
+    /// #     use diesel::dsl::json_typeof;
+    /// #     use serde_json::{json, Value};
+    /// #     use diesel::sql_types::{Json, Nullable};
+    /// #     let connection = &mut establish_connection();
+    /// let result = diesel::select(json_typeof::<Json, _>(json!({"a": "b", "c": 1})))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("object".to_string(), result);
+    ///
+    /// let result = diesel::select(json_typeof::<Json, _>(json!([1,2,3])))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("array".to_string(), result);
+    ///
+    /// let result = diesel::select(json_typeof::<Json, _>(json!("abc")))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("string".to_string(), result);
+    ///
+    /// let result = diesel::select(json_typeof::<Json, _>(json!(-123.4)))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("number".to_string(), result);
+    ///
+    /// let result = diesel::select(json_typeof::<Json, _>(json!(true)))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("boolean".to_string(), result);
+    ///
+    /// let result = diesel::select(json_typeof::<Json, _>(json!(null)))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("null".to_string(), result);
+    ///
+    /// let result = diesel::select(json_typeof::<Nullable<Json>, _>(None::<Value>))
+    ///     .get_result::<Option<String>>(connection)?;
+    ///
+    /// assert!(result.is_none());
+    /// #     Ok(())
+    /// # }
+    /// ```
+    fn json_typeof<E: JsonOrNullableJson + SingleValue + MaybeNullableValue<Text>>(e: E) -> E::Out;
+}
+
+#[cfg(feature = "postgres_backend")]
+define_sql_function! {
+    /// Returns the type of the top-level jsonb value as a text-string
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// # include!("../../doctest_setup.rs");
+    /// #
+    /// # fn main() {
+    /// #     #[cfg(feature = "serde_json")]
+    /// #     run_test().unwrap();
+    /// # }
+    /// #
+    /// # #[cfg(feature = "serde_json")]
+    /// # fn run_test() -> QueryResult<()> {
+    /// #     use diesel::dsl::jsonb_typeof;
+    /// #     use serde_json::{json, Value};
+    /// #     use diesel::sql_types::{Jsonb, Nullable};
+    /// #     let connection = &mut establish_connection();
+    /// let result = diesel::select(jsonb_typeof::<Jsonb, _>(json!({"a": "b", "c": 1})))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("object".to_string(), result);
+    ///
+    /// let result = diesel::select(jsonb_typeof::<Jsonb, _>(json!([1,2,3])))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("array".to_string(), result);
+    ///
+    /// let result = diesel::select(jsonb_typeof::<Jsonb, _>(json!("abc")))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("string".to_string(), result);
+    ///
+    /// let result = diesel::select(jsonb_typeof::<Jsonb, _>(json!(-123.4)))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("number".to_string(), result);
+    ///
+    /// let result = diesel::select(jsonb_typeof::<Jsonb, _>(json!(true)))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("boolean".to_string(), result);
+    ///
+    /// let result = diesel::select(jsonb_typeof::<Jsonb, _>(json!(null)))
+    ///     .get_result::<String>(connection)?;
+    ///
+    /// assert_eq!("null".to_string(), result);
+    ///
+    /// let result = diesel::select(jsonb_typeof::<Nullable<Jsonb>, _>(None::<Value>))
+    ///     .get_result::<Option<String>>(connection)?;
+    ///
+    /// assert!(result.is_none());
+    /// #     Ok(())
+    /// # }
+    /// ```
+    fn jsonb_typeof<E: JsonbOrNullableJsonb + SingleValue + MaybeNullableValue<Text>>(e: E) -> E::Out;
+}
diff --git a/diesel/src/pg/expression/helper_types.rs b/diesel/src/pg/expression/helper_types.rs
index 81cd81bd10a1..3e757b08872b 100644
--- a/diesel/src/pg/expression/helper_types.rs
+++ b/diesel/src/pg/expression/helper_types.rs
@@ -486,3 +486,13 @@ pub type to_jsonb<E> = super::functions::to_jsonb<SqlTypeOf<E>, E>;
 #[allow(non_camel_case_types)]
 #[cfg(feature = "postgres_backend")]
 pub type json_object<A> = super::functions::json_object<SqlTypeOf<A>, A>;
+
+/// Return type of [`json_typeof(json)`](super::functions::json_typeof())
+#[allow(non_camel_case_types)]
+#[cfg(feature = "postgres_backend")]
+pub type json_typeof<E> = super::functions::json_typeof<SqlTypeOf<E>, E>;
+
+/// Return type of [`jsonb_typeof(jsonb)`](super::functions::jsonb_typeof())
+#[allow(non_camel_case_types)]
+#[cfg(feature = "postgres_backend")]
+pub type jsonb_typeof<E> = super::functions::jsonb_typeof<SqlTypeOf<E>, E>;
diff --git a/diesel_derives/tests/auto_type.rs b/diesel_derives/tests/auto_type.rs
index 6c96ad2b20b4..7fc1ffa133cb 100644
--- a/diesel_derives/tests/auto_type.rs
+++ b/diesel_derives/tests/auto_type.rs
@@ -438,6 +438,8 @@ fn postgres_functions() -> _ {
         to_json(pg_extras::id),
         to_jsonb(pg_extras::id),
         json_object(pg_extras::text_array),
+        json_typeof(pg_extras::json),
+        jsonb_typeof(pg_extras::jsonb),
     )
 }