"In like Flynn" is a

slang Slang is vocabulary (words, phrases, and usage (language), linguistic usages) of an informal register, common in spoken conversation but avoided in formal writing. It also sometimes refers to the language generally exclusive to the members of p ...

phrase In syntax and grammar, a phrase is a group of words or singular word acting as a grammatical unit. For instance, the English expression "the very happy squirrel" is a noun phrase which contains the adjective phrase "very happy". Phrases can con ...

meaning "having quickly or easily achieved a goal or gained access as desired."

Origins

Edward J. Flynn

Etymologist

Eric Partridge Eric Honeywood Partridge (6 February 1894 – 1 June 1979) was a New Zealand– British lexicographer of the English language, particularly of its slang. His writing career was interrupted only by his service in the Army Education Corps and ...

presents evidence that it refers to

Edward J. Flynn Edward Joseph Flynn (September 22, 1891 – August 18, 1953) was an American lawyer and politician. Flynn was a leading Democratic politician of the mid-twentieth-century, known for his tight control of the Bronx Democratic Party organization af ...

(most prominent c. 1922 - 1943), a

New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the U ...

political boss In politics, a boss is a person who controls a faction or local branch of a political party. They do not necessarily hold public office themselves; most historical bosses did not, at least during the times of their greatest influence. Numerous off ...

who became a campaign manager for the Democratic party during

Franklin Delano Roosevelt Franklin Delano Roosevelt (; ; January 30, 1882April 12, 1945), often referred to by his initials FDR, was an American politician and attorney who served as the 32nd president of the United States from 1933 until his death in 1945. As the ...

's presidency. Boss Flynn's "Democratic Party machine exercised absolute political control over the Bronx.... The candidates he backed were almost automatically 'in'."

Other possible popularizations (1930-1942)

In Australia, the 1932 Ion Idriess biographical novel '' Flynn of the Inland'' about John Flynn & the Royal Flying Doctor Service, may add to the list of possible associations with the expression. Barry Popik of the