Ten Hag was only appointed Leverkusen manager in May this year.
Erik ten Hag has been sacked by Bayer Leverkusen, just three months after being chosen to succeed Xabi Alonso.
The 55-year-old, who became the Bundesliga's second-highest paid manager after signing a two-year contract worth €5.5 million (£4.7m) per year, endured a difficult start to his Leverkusen career.
His tenure began with a win over fourth-tier side Sonnenhof Grossaspach in the DFB-Pokal, but after failing to pick up a win in their opening two league games, Ten Hag has been dismissed with immediate effect.
Leverkusen confirmed the news on Monday alongside a short statement.
"Bayer 04 has parted ways with head coach Erik ten Hag with immediate effect," it read. "The assistant coaching staff will temporarily take over training duties."
The news comes just days after Leverkusen squandered a two-goal lead against Werder Bremen, where Ten Hag criticised his players and urged them to take responsibility for their poor start to the campaign.
"The players aren't ready," he admitted. "We have a new team and some of the players aren't at all fit enough to play. The team didn't function at all during the final stage of the game. That's just the way it is."
Ten Hag added: "They need to bring more intensity and get fitter in order to meet my standards. After the international break, we face real competition and must perform as a team.
"That begins with taking responsibility and delivering individual performances. And they have to demonstrate to me that they want to work together."
The former Ajax boss penned a two-year deal with Leverkusen in May, and as mentioned above, the Dutchman was on around £4.7 million per year, meaning he would be owed more than £8 million in wages.