The contract has an average annual value of $3 million, the team announced.
Sheary, 25, scored two goals and an assist in the Stanley Cup Final against the Nashville Predators. He had 17 points (six goals, 11 assists) in 45 playoff games the past two seasons, helping the Penguins win back-to-back Stanley Cup titles.
In two seasons with the Penguins, Sheary has 63 points in the regular season (30 goals, 33 assists). Last season in 61 games he had 23 goals and 30 assists in 61 games.