Dennis Kelly is a British writer and producer. He has worked in theatre, television, and film.

His play DNA, published in 2007 and first performed in 2008, became a core GCSE text in 2010 and has been studied by about 400,000 students each year. He wrote the book for Matilda the Musical, which featured music and lyrics from musician and comedian Tim Minchin. The musical went on to win multiple awards, with Kelly receiving a Tony Award for Best Book of a Musical. A film adaptation of the musical, with a screenplay by Kelly, was released in December 2022.