Fourth overall pick of the Ottawa Senators in the 2018 NHL draft who was still playing with Boston University at the time he was drafted. His primarily played left wing.
After a success freshman season at Boston University, he made the US National Team for the 2018 World Junior Championships.
He was captain of the U.S. under-18 national team at the 2017 IIHF World U18 Championships which won gold.
His father Kieth played for the Arizona Coyotes, known then as the Phoenix Coyotes. He is the younger brother of Matthew Tkachuk.
His second cousin is former NHL player Tom Fitzgerald.