Justin Samuel Halpern (born September 3, 1980) is the American author of the Twitter feed "Shit My Dad Says" and the best-selling book Sh*t My Dad Says. He was also the co-writer and co-executive producer of a CBS television situation comedy series based on the book. His second book I Suck at Girls was published in 2012 and was the basis for the 2014 television show Surviving Jack.