The 73-year-old American takes over his fifth MLS club, with prior stints at DC United (1996-98), New York Red Bulls (2006-07), Los Angeles Galaxy (2008-16) and the New England Revolution (2019-23) before resigning in September of last year.
"I'm extremely excited for the opportunity to come to San Jose," Arena said. "I coached my first ever professional game at Spartan Stadium in 1996 -- the first game in MLS history -- and my first international game with the US in 1998 was in San Jose as well."
The Earthquakes dumped coach Luchi Gonzalez in June, with Ian Russell taking charge on an interim basis to finish the season. They finished last overall in MLS at 6-25 with three drawn this year, allowing an MLS-record 78 goals.
They last reached the playoffs in 2020 and have reached the post-season only twice since 2013.
"There's a lot of potential with the club and I am looking forward to working with everyone here to unlock that potential and get back to winning ways," Arena said.
Arena, a four-time MLS Coach of the Year, owns an MLS-record 262 match wins in the regular season and a record 35 more in the playoffs.
He won three MLS Cup crowns with the Galaxy and two more with DC United while guiding the US men's national squad at the 2002 and 2006 World Cups and to three CONCACAF Gold Cup titles.
"Bruce is the most accomplished coach in American soccer history and we're thrilled to bring him to San Jose," Earthquakes managing partner John Fisher said. "He's the ideal choice to lead the Earthquakes. We know he will help get the club back to the level that San Jose and the Bay Area deserve, winning games and competing for championships."
