On August 11, 2010, D'Amigo signed a three-year, entry-level contract with the Toronto Maple Leafs. D'Amigo received a $270,000 signing bonus in addition to the average starting NHL salary of $810,000; should D'Amigo be sent to the Maple Leafs' American Hockey League affiliate, the Toronto Marlies, he would instead make $67,500 annually. D'Amigo attended Maple Leafs training camp ahead of the 2010–11 season, with Toronto having the option to keep him on their NHL roster or assign him to either the AHL or to the Ontario Hockey League 's Kitchener Rangers, who owned his major junior playing rights. He was ultimately sent to the Toronto Marlies with the open option to send him to Kitchener prior to February 10, 2011, an option the Maple Leafs eventually exercised just prior to the deadline. Before his assignment to the OHL, he had recorded 14 points in 41 games played with the Marlies. With Kitchener, he finished the 2010–11 OHL season with 12 goals and 16 assists in just 21 games played. On December 5, 2013, whilst playing with the Marlies, D'Amigo was called up to the Maple Leafs for the first time in his career, later making his NHL debut 3–2 Toronto win over the Dallas Stars. On December 14, D'Amigo scored his first career NHL goal against Antti Raanta of the Chicago Blackhawks, also registering his first career NHL assist in the game. On July 1, 2014, D'Amigo, along with a conditional seventh-round pick in 2015, was traded to the Columbus Blue Jackets in exchange for former Maple LeafMatt Frattin. D'Amigo and the Blue Jackets agreed to terms on a one-year, two-way contract on July 29, though he never played for Columbus at the NHL level during his brief tenure with the organization. Later that same year, on December 16, D'Amigo was traded to the Buffalo Sabres in exchange for forward Luke Adam. D'Amigo made his debut with the Sabres on March 3, 2015, against the Tampa Bay Lightning. After spending the 2015–16 season with the Rochester Americans in the AHL, and unable to attract a NHL contract as a free agent, D'Amigo ventured to Finland for the following season, signing with Ilves of the country's top-flight Liiga on October 16, 2016. In his first season abroad, D'Amigo quickly transitioned to the European style game in the 2016–17 campaign, contributing with 13 goals and 33 points in 48 regular season games. Following Ilves post-season exit, D'Amigo left the club as a free agent. Without a contract over the summer, he belatedly opted to continue in Finland, agreeing to a one-year contract with KalPa on October 12, 2017, for the 2017–18 season. After two seasons in Finland, D'Amigo left as free agent to sign a one-year deal with German outfit, ERC Ingolstadt of the DEL on July 17, 2018.
