Middlesbrough find themselves in a relegation battle which deepened over the weekend with defeat to bottom side Coventry.
The Riverside Stadium outfit have won just two of their eleven Championship games this season.
Wilder was appointed to replace Neil Warnock in November last year, with the club 14th on the table and they ended up finishing 7th, narrowly missing out on a playoff spot.
But a false start this term has seen them dispense with Wilder's services.
A statement released on the club's official website read: "Middlesbrough Football Club have terminated the contract of manager Chris Wilder with immediate effect.
"Leo Percovich will take over first team affairs in the interim basis, assisted by Craig Liddle, Mark Tinkler and Lee Cattermole.
"The club would like to place on record its thanks to Chris and his staff for all their hard work over the past 11 months."
Wilder was previously in charge of Sheffield United, taking them from League One to the Premier League before their relegation from the top flight last year.
