Paul Stephen Rudd was born on April 6, 1969, in Passaic, New Jersey, to English-born Jewish parents. His father, Michael Rudd (1943–2008), was a historical tour guide and former vice-president of TWA. His mother, Gloria Irene Granville, was a sales manager at television station KSMO-TV in Kansas City, Missouri. They were both from London, his father hailing from Edgware and his mother from Surbiton, and both were descended from Ashkenazi Jewish immigrants who moved to England from Belarus, Poland and Russia. His grandfather changed his paternal family's original surname, Rudnitsky, to Rudd. His maternal family's surname was Goldstein; his parents were second cousins. Rudd had a Bar Mitzvah service in Ontario, Canada. Growing up, he loved reading the British comics The Beano and The Dandy, which his uncle sent him from the United Kingdom.
When Rudd was ten, his family moved to Lenexa in Johnson County, Kansas. Because of his father's occupation, they also spent three years in Anaheim, California. In Kansas, Rudd attended Broadmoor Junior High and graduated from Shawnee Mission West High School in 1987. He attended the University of Kansas, where he majored in theater and belonged to the Sigma Nu fraternity's Nu Chapter. He studied at the American Academy of Dramatic Arts, with fellow actor Matthew Lillard. He also spent three months studying Jacobean drama at the British American Drama Academy in Oxford. While at acting school, he worked as a DJ at bar mitzvahs. After graduation, he had a variety of odd jobs, including glazing hams at the Holiday Ham Company in Overland Park.