3D Objects inside Canvas

Inside my Canvas I'm trying to display a 3D model to depict which player's turn it is alongside some text. My canvas is set to Screen Space - Overlay. My 3D game object is displaying exactly how I want it in the Editor view, but it won't appear in game.

Is is possible to have 3D game objects inside a canvas to use within UI? Or have I got the wrong end of the stick?

If it itsn't possible, is there a way to lay a game object over the top of the UI?

Thank you!