Martin was born Dean Paul Crocetti in Steubenville, Ohio in the Pittsburgh Tri-State region. His parents were Gaetano Crocetti, a barber from Abruzzi, Italy, and Angela Barra, an Italian American from Fernwood, Ohio.^[1] He spoke only Italian until age five. The traces of Italian are perhaps what lent a slight Southern drawl to Martin's speaking voice.

Martin dropped out of school in the tenth grade because, in his own words, he thought that he was smarter than the teachers. He delivered bootleg liquor, served as a speakeasy croupier, wrote crafty anecdotes and was a blackjack dealer, worked in a steel mill and boxed as welterweight. At the age of 15, he was a boxer who billed himself as "Kid Crocett" (Kro-Shey). From his prizefighting years, Martin earned a broken nose (later fixed), a permanently split lip, and many sets of broken knuckles (as a result of not being able to afford the tape used to wrap boxers' hands). He won 1 of his 12 bouts (Kehoe, John. "Dean Martin.." Biography 4.10 (2000): 124. History Reference Center) The prize money was small. For a while he roomed with Sonny King, who like Martin, was just starting out in show biz and had little money. Martin and King held bare knuckle matches in their apartment, fighting until one of them was knocked out; people paid to watch the sight.

Eventually, Martin gave up boxing. He worked as a roulette stickman and croupier in an illegal casino located behind a tobacco shop where he had started out as a stock boy. At the same time, he sang with local bands. Billing himself as "Dino Martini" (after the then-famous Metropolitan Opera tenor, Nino Martini), he got his first break working for the Ernie McKay Orchestra. He performed in a crooning style heavily influenced by Bing Crosby and Harry Mills (of the Mills Brothers), among others. In the early 1940s, he started singing for bandleader Sammy Watkins, at which time Sammy suggested he change his name to Dean Martin.

In October of 1941, Martin married Elizabeth Anne McDonald, and during their marriage (ended by divorce in 1949), they had four children. Martin worked for various bands throughout the early 1940s, more on looks and personality than vocal ability until he developed his own smooth singing style. Martin famously flopped at the Riobamba when he succeeded Frank Sinatra there in 1943, but it was the setting for the two men's introduction.

To earn extra money, Martin repeatedly sold 10% shares of his earnings for upfront cash. Martin apparently did this so often that he found he had sold over 100% of his income. Such was the power of his charm that most of his lenders forgave his debts and remained friends.

After being drafted into the United States Army during World War II, Martin served a year (1944-45) in Akron, Ohio. He was then classified 4-F (possibly due to a double hernia; Jerry Lewis referred to the surgery Martin needed for this in his autobiography) and was discharged.

By 1946, Martin was doing relatively well, but he was still little more than an East Coast nightclub singer with an all-too-common style, similar to that of Bing Crosby. He could draw audiences to the clubs he played, but he inspired none of fanatic popularity enjoyed by Sinatra.