Early career Donato played high school hockey with
Dexter Southfield in
Massachusetts. He was selected in the second round, 56th overall, by the
Boston Bruins in the
2014 NHL entry draft. Continuing to play with Dexter, Donato made his junior debut with the
South Shore Kings in the
United States Premier Hockey League before finishing with the
Omaha Lancers of the
United States Hockey League, having committed to a collegiate career with
Harvard University, in following his father's footsteps who was now the Crimson's head coach.
Professional Boston Bruins Having led the Crimson as a junior in scoring through the
2017–18 season with 26 goals and 17 assists for 43 points in just 29 games, Donato opted to leave the college early and turn professional. He signed a three-year, entry-level contract with the Bruins on March 18, 2018. Despite leaving college hockey, Donato was still enrolled in Harvard classes and was aiming to finish the semester while playing in the NHL. He made his NHL debut the next day where he recorded his first NHL goal and added two assists in a 5–4 overtime loss to the
Columbus Blue Jackets. Donato made his playoff debut during Game 2 of the
2018 Stanley Cup playoffs in a 7–3 win over the
Toronto Maple Leafs. Donato began the
2018–19 season with the Bruins. On November 1, he was assigned to the Bruins'
American Hockey League (AHL) affiliate, the
Providence Bruins after playing in 11 games. He was recalled by Boston on November 28 after recording nine points in 10 games for Providence. Donato was reassigned to Providence on January 28, 2019.
Minnesota Wild On February 20, 2019, Donato and a
2019 conditional fifth-round pick were traded to the
Minnesota Wild in exchange for
Charlie Coyle. He made his debut for the Wild on February 21, recording two assists in a 4–1 win over the
New York Rangers. On July 16, 2019, the Wild re-signed Donato to a two-year, $3.8 million contract extension.
San Jose Sharks On October 5, 2020, Donato was traded by the Wild to the
San Jose Sharks in exchange for
Pittsburgh's
2021 third-round pick. His debut came on January 14, 2021, in a 4–3 shootout win over the
Arizona Coyotes.
Seattle Kraken On September 12, 2021, the
expansion team Seattle Kraken signed Donato as a free agent to a one-year, $750,000 contract for the
2021–22 season. Donato scored the opening goal in the franchise's first preseason game against the Vancouver Canucks on September 26, 2021. He followed that up with the first official goal in Seattle Kraken franchise history, scoring on opening night in a 4–3 loss to the
Vegas Golden Knights on October 12, 2021. Donato scored a career-high 16 goals and added 15 assists for 31 points in 74 games, as Seattle missed the playoffs in their inaugural season. As an impending restricted free agent, Donato was not tendered a qualifying offer by the Kraken and was released as a free agent. On July 27, 2022, after testing the market he was re-signed by the Kraken to a one-year, $1.2 million contract. In the
2022–23 season, Donato built upon his first season with the Kraken by continuing to contribute in various forward roles in posting 13 goals and 27 points through 71 regular season games. In helping the Kraken qualify for the post-season, he added 2 assists through 14 games.
Chicago Blackhawks After two seasons with the Kraken, Donato left the club as a free agent and was signed on the opening day of free agency to a two-year, $4 million contract with the rebuilding Chicago Blackhawks on July 1, 2023. On March 28, 2025, Donato scored his first career
hat-trick in a 5–3 loss to the Vegas Golden Knights. On June 18, 2025, Donato signed a four-year, $16 million contract extension with the Blackhawks. ==International play==