Kevin Joseph Costello FRS is an Irish mathematician, since 2014 the Krembil Foundation's William Rowan Hamilton chair of theoretical physics at the Perimeter Institute in Waterloo, Ontario, Canada.

[1][3] Costello was educated at the University of Cambridge where he was awarded a PhD in 2003[4] for research on Gromov–Witten invariants supervised by Ian Grojnowski.

Using this language, Costello gave a rigorous construction of the Witten genus in elliptic cohomology, using a variant of Chern–Simons theory.

[6] Along with Davide Gaiotto, Kevin Costello was one of two researchers appointed to named chairs by the Perimeter Institute in 2014, funded by a $4 million investment by the Krembil Foundation.

Costello's appointment was praised by Fields medalists Maxim Kontsevich and Edward Witten.