The Browns also dismissed offensive coordinator Todd Haley, the person said. Haley was in his first season on Jackson's staff after spending the previous six in Pittsburgh.
Jackson's firing came a day after the Browns (2-5-1) lost their 25th straight road game — 20 of them coming with Jackson in charge.
The Browns, who have not made the playoffs since 2002, have lost three straight games after a promising start to this season. They tied Pittsburgh in Week 1, but were beaten 33-18 on Sunday by the Steelers.
Jackson is the sixth straight Cleveland coach to be fired following the team’s second game against Pittsburgh. Romeo Crennel, Eric Mangini, Pat Shurmur, Rob Chudzinski and Mike Pettine all met the same demise.
It's not immediately clear who will fill in for Jackson for the rest of this season. The Browns host the Kansas City Chiefs (7-1) on Sunday.
Defensive coordinator Gregg Williams and wide receivers coach Al Saunders are interim candidates capable of finishing the season. Williams and Saunders both have previous head coaching experience.
Jackson was hired in 2016 by owners Dee and Jimmy Haslam, who stuck by him despite a 1-15 record in his first season and the Browns losing all 16 games last season, joining the 2008 Detroit Lions as only the second team in league history to go 0-16.
But beyond the lopsided losses, quarterback changes and bad luck, the Browns have been constantly saddled with drama and dysfunction under Jackson, who came to Cleveland after serving as Cincinnati's offensive coordinator and went 8-8 as Oakland's head coach in 2011.
Last week, Jackson’s offer to help Haley following a loss in Tampa Bay underscored another power struggle as Jackson fought to stay in control.
Following Sunday’s game, Jackson downplayed any dispute with his offensive coordinator.
“There’s nothing wrong with my relationship with Haley,” Jackson said. “I never said I wanted to take over play-calling. I said wanted to help, that’s it. But today it’s this big thing because sure, everyone is going to look and say what’s going on. The only thing that is going on is that we need to get better. We need to coach better, we need to play better.”
Jackson’s firing comes one day after the Cleveland Cavaliers fired coach Tyronn Lue, who led the team to an NBA title in 2016 but was struggling in his first season without star LeBron James. The Cavs are 0-6.