The Bengals fired Lewis as the team's head coach on Monday morning, the team announced
Lewis, who received NFL Coach of the Year honors in 2009, was the second-most tenured coach in the league behind Bill Belichick of the New England Patriots.
"I want to thank the Bengals' organization, the fans and the city of Cincinnati for their support," the 60-year-old Lewis said. "I regret I haven't been able to provide them with the No. 1 goal of being world champions. I also want to thank our players, coaches and team employees for their effort and professionalism over the past 16 years. A lot of fine people have gone through this building in that time, and the organization is better for all of them having been a part of it."
Lewis had one season remaining on a contract extension he signed last year.
"The team is very appreciative of all that Marvin has accomplished over the past 16 years," team president Mike Brown said. "Personally, I am very fond of Marvin and will miss working with him. He is a friend and a colleague, and I thank him for what he has meant to this franchise. But it is time to turn the page and look toward the next chapter for our organization, and we are excited about what the future holds for the team and our fans."
The Bengals answered a 4-1 start to the 2018 season by losing nine of 11 contests to finish with a 6-10 mark.
Lewis posted a 131-122-3 record during his time on the sideline, with his win total serving as a franchise record.
His postseason mark (0-7) left plenty to be desired, however.
Lewis has led the Bengals to the postseason seven times, including five straight years from 2011 to 2015, but the team has not won a playoff game since 1991.
Cincinnati won AFC North titles under Lewis in 2005, 2013 and 2015.