The 29-year-old joined the Andalucian outfit in their B team from Nervion in 2003 and has been with the first team since 2008.
Varas’ impressive performances for the Primera Division side have now been rewarded with an extended deal, and a buy-out clause of €20 million has been inserted into his new contract.
The Spanish custodian is pleased to have stretched his stay at the Ramon Sanchez Pizjuan and told Sevilla’s official website: "It's an important day for me and my family.
“What has led to this situation is my work and my professionalism and I thank the club for rewarding me for the job I've done and for keeping confidence in me."
Varas has featured in six matches in the league so far this season for Sevilla, who are sixth in the table with 12 points from six matches.