Margaret J. Winkler Mintz (April 22, 1895 – June 21, 1990) was a key figure in silent animation history, having a crucial role to play in the histories of Max and Dave Fleischer, Pat Sullivan, Otto Messmer, and Walt Disney.

It was a good thing, because at the end of the same year the Fleischer brothers, flush with success as a result of Winkler's work, left her to form their own distribution company, Red Seal Pictures.

In September 1923, the renewal of his contract came up, and his unrealistic demands meant M.J. Winkler Pictures might have to survive for a while without its biggest star.

Disney was helped by the tutelage of Winkler, who insisted on editing all of the "Alice Comedies" episodes herself.

This was apparently the "straw that broke the camel's back" for Sullivan, who signed with rival distributor E. W. Hammons of Educational Pictures in 1925.

Soon after she had her first child and retired from the business, turning her company over to her husband who renamed it Winkler Productions in 1926.