John Deasy (born 8 October 1967) is an Irish former Fine Gael politician who served as a Teachta Dála (TD) for the Waterford constituency from 2002 to 2020.

Deasy studied at Mercyhurst College, Erie, Pennsylvania,[2] on a golfing scholarship where he received a Bachelor of Arts in History and Communications.

Deasy was also legislative assistant in the United States House of Representatives, handling trade, foreign affairs, energy, environment, banking, economic development, immigration and human rights, for Congressman Ronald Machtley.

In January 2007, he announced his intention to challenge Enda Kenny's leadership of Fine Gael, should the party fail to enter government after the 2007 election.

[5] In June 2019, the Fine Gael organisation in Waterford constituency passed a motion of no confidence in Deasy, supporting his longtime rival Paudie Coffey.