Silva has put pen-to-paper for one more year at the Reale Arena.
The 37-year-old joined Sociedad in the summer of 2020 on a free transfer after leaving Manchester City, where he won four Premier League titles, four FA Cups and five League Cups in ten years.
Silva has made 90 appearances for Sociedad in his time at the club, scoring six goals and providing 15 assists.
The former Spain international has been instrumental in Sociedad's push for Champions League football this season, with the club fourth in La Liga with just five games left to play.
Silva said: "I feel very comfortable here, both my family and I, and the team is doing very well, so these are all positive things.
"I have to be honest with myself, I feel very well physically and I want to continue.
"The group is good, with healthy and young people, eager to learn. I am the oldest, the one who always makes demands on others, because I went through that period where I was young and I didn't know anything. I was a bit lost, and it's important when there are people with more experience who help you."
Silva won 125 caps for Spain and was an integral part of their squads that won the European Championships in 2008 and 2012, as well as the 2010 FIFA World Cup.
