John Hegarty (born 1948) is an Irish physicist and academic who served as the 43rd Provost of Trinity College Dublin from 2001 to 2011.

[1] He was born in Claremorris, County Mayo, and was educated locally at St Colman's College.

[1] Following a postdoctoral stay at the University of Wisconsin–Madison, he was a research scientist at Bell Labs, New Jersey for six years.

Producing over 140 publications, and developing several patents, he was a co-founder of Optronics Ireland and campus company Eblana Photonics.

[1] Hegarty is married to Neasa Ní Chinnéide, President of the European Bureau for Lesser-Used Languages,[2] and they have two children, Cillian and Ciarán.