A universal treetop mount for fixedly coupling a treetop decorative light to the top end of the main body of a tree-shaped decoration includes a mount body whose bottom side has a connecting portion for coupling with the main body of the tree-shaped decoration, and whose top side forms an upper mount surface for coupling with the treetop decorative light. A hollow positioning tube extends upward from a central position on the upper mount surface and is peripherally provided with a position-limiting groove. Blocking units are provided around the position-limiting groove to retain an object received in the position-limiting groove. When the connecting portion, which includes a connecting tube and a clamping unit, is coupled with the main body of the tree-shaped decoration, the connecting tube is coupled with a connected portion at the top end of a main trunk, and the clamping unit is clamped to the connected portion.