Defensive coordinator Wade Phillips was named the interim head coach for the final three games of the 2013 season, but there are no guarantees for him beyond that.
A Super Bowl favorite to some this year, the Texans have lost 11 straight games en route to a 2-11 record. They're currently in line to make the first overall pick in the 2014 draft.
Let's look at the top head-coaching candidates for Houston.
Yes, Kevin Sumlin just signed a six-year contract extension with Texas A&M. No, that doesn't mean he absolutely has to stay there.
While it's rather unlikely that he leaves the Aggies, if the Texans are willing pay him an exorbitant amount of money, Sumlin could bolt for the NFL.
We've seen it happen before with hot college coaches.
Sumlin's University of Houston teams were offensive juggernauts—just ask Case Keenum—and Texas A&M certainly hasn't had any problem scoring points over the past two seasons with Sumlin at the helm.
The Cougars averaged 37.7 points per game in 2010 and led the NCAA in scoring with 49.3 points per game in 2011.
Texas A&M scored 44.5 points per game in Sumlin's first year in College Station and will head into this season's bowl game with a 43.6-point average.
Texans owner Bob McNair may very well be aggressive in his pursuit of Sumlin because he's a respected and established in-state coach.
Darrell Bevell is another offensive-minded coach who'd fit well in Houston.
Russell Wilson had a tremendous rookie season not many saw coming, and in 2013, he's played at an Offensive Player of the Year level.
Bevell likes to run the football, but the job he's done with Wilson will be enticing for a team that'll likely start a rookie at quarterback in 2014.
Texans fans might cringe at the idea of Ken Whisenhunt as the team's next head coach, but he would make sense for a variety of reasons.
Sure, he was fired by the Arizona Cardinals after the 2012 season.
However, Whisenhunt's been largely responsible for Philip Rivers' career resurgence in 2013 as the San Diego Chargers offensive coordinator, and he held the same position with the Pittsburgh Steelers when Ben Roethlisberger began his NFL career.
Per Football Outsiders, no team currently averages more yards per drive than the Chargers, and Rivers is completing 70 percent of his passes. He's on pace to throw for more than 4,800 yards with 31 touchdowns and only 12 interceptions.
While Whisenhunt might be best suited as an offensive coordinator, the Texans might be interested in him due to his quarterback-whispering past.
Sean Payton is the offensive play-caller for the New Orleans Saints, but his right-hand man since 2009 has been offensive coordinator Pete Carmichael.
Drew Brees has set a handful of records while Carmichael's been the OC, and the Saints are annually one of the most prolific offensive clubs in the NFL.
Would the Texans want to bring Payton's pass-predicated system to Houston?
Carmichael could be interested in the job because he'd likely have his pick of the quarterback-prospect litter in May's draft.
Lovie Smith sat out the 2013 season after being fired by the Chicago Bears despite finishing with a 10-6 record in 2012.
He's more subdued than most NFL head coaches, but he does have a vast defensive background, and his Chicago teams ran the 4-3 defense with a relatively great deal of success.
Smith's a likely candidate if interim head coach Wade Phillips isn't retained at season's end.
According to FOX Sports' Mike Garafolo, during Bob McNair's press conference announcing Kubiak's firing, the Texans owner indicated that Smith will be considered for the head-coaching vacancy.
Mike Zimmer's been a hot head-coaching candidate for years now, and he continues to field an upper-echelon defense in Cincinnati.
A fiery, in-your-face defensive mind who isn't necessarily a 3-4 or 4-3 guy, Zimmer could be appealing to the Texans based on the fact that they do have a few elite defenders already on the roster.
Ray Horton is another rather young, highly sought-after head-coaching candidate with a background in an ultra-aggressive 3-4 defense.
He worked wonders with the Arizona Cardinals defense during the 2011 and 2012 seasons, which led to him being hired by the Cleveland Browns in 2013.
Currently, the Browns are allowing the fewest yards per drive in the NFL, per Football Outsiders.
The main issue standing in the way of Horton being named the next head coach of the Texans is that he employs a "two-gap" 3-4 system, one in which the defensive linemen are asked to occupy blockers and not necessarily penetrate the backfield.
One would assume that type of defense wouldn't be the greatest way to utilize J.J. Watt.
The Blue Devils, far from a football powerhouse, have won 10 games this season and will play No. 1 Florida State in the ACC title game this weekend.
This comes after they qualified for a bowl game in 2012.
Cutcliffe certainly has elevated the Duke program to unprecedented heights.
His quarterback specialty could interest Bob McNair, as the Texans will likely look for a franchise quarterback early in the 2014 draft.
Like Kevin Sumlin, David Shaw appears to be content with his current collegiate head-coaching job and recently signed a long-term extension to stay in the NCAA ranks.
But also like Sumlin, he could leave for the NFL if the money and the situation are attractive enough.
Since taking over the Stanford head job in 2011, Shaw's teams have lost only six games, and his offensive philosophy is rooted in traditional, run-heavy concepts.
The venerable John McClain of the Houston Chronicle (via NFL.com's Ian Rapoport) "believes the Texans will look at Shaw" and that "he hasn't closed the door on an NFL job."