An auctioneer from Bandon, County Cork, Crowley was an accomplished rugby player in his youth. He and his wife Sally had six children. Their son Brian Crowley is a former Fianna Fáil senator, and has been a Member of the European Parliament (MEP) since 1994.
He stood unsuccessfully as a Fianna Fáil candidate for Dáil Éireann in the Cork Mid constituency at a by-election in March 1965, but won the seat at the 1965 general election in April. After boundary changes for the 1969 general election, he was re-elected in the new Cork South–West constituency, and held the seat at the 1973 general election. Meanwhile, he had been elected in 1967 as a member of both Cork City Council and Cork County Council, and after the 1971 local elections had remained a member only of the County Council.
He lost his seat at the 1977 general election. Fianna Fáil won a landslide victory, but it had fielded three candidates in Cork South–West and won only one seat. Crowley, the sitting TD, was beaten by his party colleague Joe Walsh. He was then elected to the 14th Seanad Éireann on the Cultural and Educational Panel, and at the 1981 general he regained his Dáil seat from Walsh. Walsh retook the seat at the February 1982 general election, following which Crowley stood in the Seanad elections on the Cultural and Educational Panel. However, he did not win a seat; at the time Fianna Fáil was deeply divided between supporters and opponents of its leader Charles Haughey, and the Haughey-supporting Crowley was beaten by another Fianna Fáil candidate, Séamus de Brún, who had previously been nominated by the Taoiseach, Jack Lynch to the 14th Seanad. Crowley was then nominated by Haughey to the 16th Seanad.
- "Mr. Flor Crowley". Oireachtas Members Database. Retrieved 25 February 2008.
- "Death of Mr Flor Crowley". The Irish Times. 17 May 2007. Retrieved 20 February 2008.
- "Brian Crowley". ElectionsIreland.org. Retrieved 25 February 2008.
- "Flor Crowley". ElectionsIreland.org. Retrieved 25 February 2008.
- "Taoiseach's nominees to the Senate". The Irish Times. 11 May 1982. p. 6. Retrieved 7 February 2008.
- Denis Coghlan (22 April 1982). "Senate defeat for Flor Crowley". The Irish Times. p. 1. Retrieved 7 February 2008.
- "Senate results". The Irish Times. 2 March 1983. p. 6. Retrieved 7 February 2008.
- "Ahern praises Flor Crowley". The Irish Times. 19 May 2007. Retrieved 20 February 2008.