Clancy Wiggum was possibly born in Baltimore, Maryland. He mentioned he used to sell ribbons there with his father, Iggy Wiggum. Iggy was a World War II veteran who died in a parade float accident in 1979. He did, however, grow up in Springfield and was among the same class and age group as Homer Simpson, Lenny Leonard, Carl Carlson, Barney Gumble, and Marge Simpson (née Bouvier). At an early age Wiggum played cops and robbers with Homer and other kids his age and he showed a clear ambition to become a police officer. At the age of 16, he was a hall monitor at high school, and possibly had a part-time security guard job at Springfield State University. Wiggum was present at the University's germ research labs (Prof. C. Montgomery Burns was chairman at the time) when Mona Simpson and the hippie activist group she was part of sabotaged the germ experiments. Wiggum, who had suffered from asthma prior to that, was cured by antibiotics that the group released to kill the germs, and helped Mona Simpson escape the police when she was on the run twenty-five years later for curing his asthma & making the police force.
In 1985 Wiggum was involved in the barbershop quartet called the Be Sharps. Wiggum was a member with Homer Simpson, Seymour Skinner, and Apu. However, a talent scout showed interest in the Be Sharps but didn't like Wiggum as a performer (for being too "Village People"), so he was thrown out of the group. When auditions were held to find a replacement for Wiggum, he attempted to be reselected for the quartet. He wore a disguise, but was found out.
Early attempts to get into the police force when he was a teenager were unsuccessful on account of his asthma, so when it had been cured he could then pursue his ambition to become a professional police officer. Having entered the Police Academy by age 24, Wiggum managed to work around his many shortcomings by providing superiors with wonderful back rubs using the handle of his gun, and finally become a full fledged officer and by 32, he had managed to work his way up to the position of Police Chief of Springfield. In contradiction to this Wiggum reveals in the episode "Papa's Got a Brand New Badge" that he got his job by chance, as a former police officer had offered his badge to the next passerby who happened to be Wiggum.
Wiggum is promoted to Commissioner of Police for Springfield's state in Pranksta Rap.