The real Leopold, Duke of Albany, died of hemophilia in 1884 at age 31.

The movie was re-edited days before its release because critics at one of the press screenings noticed a glaring problem. Originally, Leopold was Stuart's great, great grandfather. Since Kate eventually went back in time to be with Leopold, she would be Stuart's great, great grandma as well. Talked about whacked out incest. Most instances of that relationship were removed (it is alleged that Leopold's line "I felt that we met before on a previous occasion" early on was left in by mistake,) though it is explained on the director's cut version on the DVD.

In the scene where Leopold is writing a letter to Kate inviting her to dinner on the roof, he's writing with the quill in his right hand. Hugh Jackman is left handed.