diff --git a/ibis/expr/datatypes/cast.py b/ibis/expr/datatypes/cast.py
index 2eceef7049e2..baabfd00e082 100644
--- a/ibis/expr/datatypes/cast.py
+++ b/ibis/expr/datatypes/cast.py
@@ -54,6 +54,8 @@ def can_cast_subtype(source: dt.DataType, target: dt.DataType, **kwargs) -> bool
 @castable.register(dt.Integer, (dt.Floating, dt.Decimal))
 @castable.register(dt.Floating, dt.Decimal)
 @castable.register((dt.Date, dt.Timestamp), (dt.Date, dt.Timestamp))
+@castable.register(dt.String, dt.JSON)
+@castable.register(dt.JSON, dt.String)
 def can_cast_any(source: dt.DataType, target: dt.DataType, **kwargs) -> bool:
     return True
 
diff --git a/ibis/expr/datatypes/core.py b/ibis/expr/datatypes/core.py
index 3dad910e753c..8c0c8c166be3 100644
--- a/ibis/expr/datatypes/core.py
+++ b/ibis/expr/datatypes/core.py
@@ -773,7 +773,7 @@ def _pretty_piece(self) -> str:
 
 
 @public
-class JSON(String):
+class JSON(Variadic):
     """JSON values."""
 
     scalar = ir.JSONScalar