Ronn Tomassoni (born March 1958) is a retired American ice hockey player and coach. Tomassoni was part of the coaching staff at Harvard for 17 years in various capacities and helped the team with its only national title in 1989.

Ronn Tomassoni played for Rensselaer in the late 1970s, posting average numbers over four seasons. After graduating in 1980 Tomassoni continued his involvement with hockey by becoming an assistant coach for Bill Cleary at Harvard in 1982.^[1] Tomassoni's arrival coincided with the Crimson's return to prominence as they began to make the NCAA Tournament annually. As time went on Cleary began to rely on Tomassoni more heavily, promoting him to associate status and effectively turning over the recruiting responsibilities to him.^[2] Tomassoni was part of Harvard's national title team in 1989 and was named as head coach when Cleary became athletic director after the 1989-90 season.^[3]

The early years under Tomassoni were very good in Cambridge as Harvard won three consecutive regular season titles, an ECAC title and made it to the 1994 Frozen Four. After 1994, however, Tomassoni could not get Harvard to produce a winning season. He held onto the job for five seasons before deciding to resign after the 1998–99 season. Tomassoni returned to his native Minnesota afterwards, settling in Duluth.^[4]

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