Denis Leary, a Worcester, Massachusetts native, was born to Irish immigrant parents, Nora (Sullivan) and John Leary, who had grown up together. His mother, a maid, and his father, an auto mechanic, instilled in him a strong sense of roots and identity.
Growing up in the 1960s, Leary developed a passion for acting and writing, which he pursued at Emerson College in Boston. He was a charter member of Emerson's Comedy Workshop and even taught at the college for five years after graduating. During this time, he honed his writing skills by penning pieces for magazines and worked on his stand-up comedy routine.
In 1990, Leary and his wife, Ann Leary, traveled to London to perform in the BBC's Paramount City. However, their planned weekend trip was cut short when Ann's water broke, and they ended up staying in London for months. During this time, Leary, with the help of friends from the States, wrote a one-man comedy act. He brought in Chris Phillips and Adam Roth on guitar, and together they performed "No Cure for Cancer" at the Edinburgh International Arts Festival in Scotland.
Despite some controversy surrounding the title, the show won the Critic's Award and the BBC Festival Recommendation. The following year, the show was brought to America, where it was eventually taped and broadcast on Showtime. The show's success spawned a book, CD, cassette, and videotape, as well as Leary's film career.
Since then, Leary has starred in numerous films and had two of his own TV series.