Born in Jersey City, New Jersey, he was one of 18 children in an impoverished household. After years of bouncing from foster homes to reform school, 16-year-old Wilson lied about his age and joined the United States Air Force. His outgoing personality and funny stories made him popular; he was even asked to tour military bases to cheer up other servicemen. Claiming that he was always "flipped out", Wilson's barracks mates gave him his famous nickname. Discharged in 1954, Wilson started working as a bellhop in San Francisco's Manor Plaza Hotel.
At the Plaza's nightclub, Wilson found extra work playing a drunken patron in between regularly scheduled acts. His inebriated character proved popular and Wilson began performing it in clubs throughout California. He managed to get jobs at various comedy clubs using his nickname, Flip. At first Wilson would simply ad-lib on-stage, but in time, he added written material and his act became more sophisticated.
The show aired through 1974, gaining high ratings and popularity among viewers. It also won strong critical acclaim, nominated for 11 Emmys during its run, winning two. Wilson himself won a Golden Globe award for Best Actor In A Television Series.
He also won a Grammy Award in 1970 for his comedy album "The Devil Made Me Buy This Dress".
Wilson's stand-up comedy routine "Columbus," from his album Cowboys and Colored People, earned him the good notices which led to his getting his own television show. Wilson re-tells the story of Christopher Columbus from a slightly 'urban' perspective, with Columbus finally convincing the Spanish monarchs to fund his voyage by noting that discovering America means that he can thus also discover Ray Charles. Hearing this, Queen Isabella, sounding not unlike Wilson's celebrated "Geraldine," says that "Chris" can have "all the money you want, Honey — You go find Ray Charles!!" When Columbus departs from the dock, Isabella is there, testifying to one and all that "Chris gonna find Ray Charles!!"
He made many guest appearances on other TV comedies and variety shows, such as Here's Lucy starring Lucille Ball and The Dean Martin Show among others. Ed Sullivan gave Wilson numerous guest shots on his popular Sunday night show, and Wilson would single out Sullivan as providing his biggest career boost. Wilson acted in TV and theatrical movies including Uptown Saturday Night and The Fish that Saved Pittsburgh.
From 1985 to 1986, Wilson played the lead role in the sitcom Charlie & Co..
One of Wilson's best-known jokes was relayed as follows: "Lots of crazy things happen in traveling. Just last week I was on a train. There was a woman traveling with a baby. UGLY baby! I mean, I'm not one to make comments about anyone's kid -- but this was an UGLY baby. A guy walks down the train -- he's half smashed -- and he stops. And he stares. And the lady says "What are you looking at?" The guy says "I'm looking at that ugly baby." A scene ensues, whereupon the conductor arrives. He says "What's going on here?" The woman says "This man just insulted me!" The conductor says "Now calm down Madam, calm down. We here at the railroad want to make sure that there are no altercations between our passengers and that everyone's trip is as relaxing as possible. Accordingly, if you allow us, please step into the dining car and the railroad will buy you a free meal. And maybe we can find a banana for your monkey."