McKenzie told reporters during a news conference called to introduce himself as the team's new GM that Jackson had been axed following the team's 8-8 performance in a season marked by the death of longtime owner Al Davis.
"Early this morning, I informed coach Hue Jackson that he was relieved of his head-coaching duties," McKenzie said. "I wished him well as he moved forward into his future."
McKenzie, a former Raiders linebacker, took over as GM Friday after spending 18 years in the front office of the Green Bay Packers.
Jackson's fate was apparently sealed after the Raiders failed to make the playoffs despite needing only a victory over San Diego on the final day of the season to win the AFC West.
The Denver Broncos instead took the title as the Raiders lost to the Chargers 38-26 at home, finishing the season with four losses in five games.
Speculation centered on Packers assistant Coach Winston Moss as a candidate to replace Jackson.