The 35-year-old Argentinian was the second veteran Inter defender to commit himself to the Nerazzurri after Javier Zanetti also signed a 12-month deal on Wednesday.
Samuel joined the Italian giants in 2005 from Real Madrid in a big-money move and has been a regular feature when fit, making over 200 appearances for the club.
"I'm very happy to have renewed my contract for another year," he told the club's official website.
The centre-half is now determined to help Inter's cause as they bid to put last season's disastrous ninth-place finish in Serie A behind them.
"Along with my team-mates, I hope I can give Inter a positive year and repay the club for the faith they've shown, since they still believe in me," he added.