| John J. Delaney | |
| Image Name: | John James Delaney.jpg |
| State1: | New York |
| District1: | 7th |
| Term Start1: | November 3, 1931 |
| Term End1: | November 18, 1948 |
| Preceded1: | John Quayle |
| Succeeded1: | Louis B. Heller |
| Term Start2: | March 5, 1918 |
| Term End2: | March 3, 1919 |
| Preceded2: | John J. Fitzgerald |
| Succeeded2: | James P. Maher |
| Birth Date: | August 21, 1878 |
| Birth Place: | Brooklyn, New York, USA |
| Death Place: | Brooklyn, New York, USA |
| Restingplace: | Holy Cross Cemetery, Brooklyn, New York |
| Spouse: | Lotti S. Borchert (m. 1925–1948, his death) |
| Children: | 2 |
| Profession: | Attorney |
| Party: | Democratic |
| Education: | Manhattan College Brooklyn Law School |
John Joseph Delaney (August 21, 1878 - November 18, 1948) was an American lawyer and politician who served ten terms as a United States representative from New York from 1918 to 1919, and then from 1931 to 1948. He was elected to an 11th term in 1948 but died shortly after the election.
Delaney was born in Brooklyn, he attended St. Ann's Parochial School and St. James' Academy in Brooklyn and Manhattan College. He engaged in the diamond business in 1897, was graduated from the Brooklyn Law School of St. Lawrence University in 1914, was admitted to the bar in 1915 and commenced practice in New York City.
Delaney was elected as a Democrat to the Sixty-fifth Congress, by special election, to fill the vacancy caused by the resignation of Representative John J. Fitzgerald, and held office from March 5, 1918, to March 3, 1919.
He declined to be a candidate for renomination in 1918 and resumed his former business pursuits. He was a delegate to the Democratic State conventions in 1922 and 1924 and was deputy Commissioner of Public Markets of New York City from 1924 to 1931.
He was again elected as a Democrat to the House of Representatives, this time to the Seventy-second Congress, to fill the vacancy caused by the death of Representative-elect Matthew V. O'Malley.
Delaney was reelected to the eight succeeding Congresses, holding office from November 3, 1931, to November 18, 1948. He was reelected in 1948 to the Eighty-first Congress but died on November 18, 1948, in Brooklyn.
Interment was in Holy Cross Cemetery.