The Bruins also signed forward Brett Connolly to a one-year contract with a cap figure of $1,025,000. Forward Brandon DeFazio got a one-year, two-way contract worth a cap figure of $575,000 at the NHL level.
Hayes is a Boston native who played 72 games for the Florida Panthers last season and had 19 goals and 16 assists. He was acquired from the Panthers last week for forward Reilly Smith and the contract of center Marc Savard, who has not played since 2011 because of post-concussion syndrome.
The 25-year-old Hayes helped Boston College win the national championship in 2010.