Zubrus had been on a professional tryout with the Sharks before signing the deal Tuesday. He is expected to make his debut for the team on Wednesday night against Chicago.
The 37-year-old had four goals and six assists in 74 games with New Jersey last season. He played for Sharks coach Peter DeBoer from 2011-14 with the Devils.
Zubrus has 225 goals and 359 assists in 1,243 career games with Philadelphia, Montreal, Washington, Buffalo and New Jersey.
The Sharks also reassigned forward Nikolay Goldobin to the Barracuda of the AHL.