The termination was reported by ESPN's Dan Graziano and Adam Schefter and later confirmed by the team.
O'Brien was let go a day after the team dropped its fourth straight game to start the 2020 season.
Shortly after being let go, O'Brien gave his final remarks as a member of the ball club to reporters, offering gratitude for all that his team accomplished under him, as well as recognizing everything the city of Houston has given him and his family.
You can watch his final remarks in the video above.
The Texans offered a statement confirming O'Brien was let go and Romeo Crennel, the team's assistant head coach, was appointed as the interim head coach.
The following is a statement from Texans Chairman and Chief Executive Officer Cal McNair:
"On behalf of my family and our entire organization, I want to sincerely thank Bill O'Brien and his family for their impact on our franchise. Bill's leadership moved our organization forward as he guided us to four AFC South division championships, 52 wins and multiple playoff appearances during his tenure. Bill proved himself as a coach and leader in this league. I spoke with him earlier today and told him we are moving in a different direction. Romeo Crennel will serve as our interim head coach for the remainder of the 2020 season. We have a talented team and I have no doubt our players and staff will rally to make Texans fans proud as we aim to win championships and do great things for the city of Houston."
O'Brien, who turns 51 on Oct. 23, was first hired by the Texans in 2014. He was appointed as GM before this current season.
SEE MORE: Texans fans take over social media after Bill O'Brien gets the boot: 'Finally!'
His current contract was set to run through 2022. As for the GM role, the team did not say who would fill in. Before O'Brien was appointed to the front-office position, the Texans had played through the 2019 season without anyone under that title.
A statement from Cal McNair. pic.twitter.com/5JbZylPTbp— Houston Texans (@HoustonTexans) October 5, 2020
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