Joshua Samuel Donn (born June 1, 1982 in Knoxville, Tennessee) is a multi national champion and a gold medal world junior champion in contract bridge. He is known as a bridge lecturer as well as author. Donn is an American Contract Bridge League Grand Life Master. He is the all-time leader of Richard Pavlicek's monthly polls that ran from 2000–2006 and had thousands of participants from over 90 countries. He currently resides in Las Vegas, Nevada with his daughter.
Donn authored a popular online column called "Breakin' the Rules" from 2011 to 2015. He co-authored a book called More Breaking the Rules: Second Hand Play with Barry Rigal in 2013. He also has moderated and written a column in the ACBL Bridge Bulletin called "The Bidding Box" since 2021.