The action was taken after "careful consideration" and was effective immediately, the studio said in a statement. No decision has been made on the show's future without its star, Warner spokesman Paul McGuire said.
Sheen, 45, who has used TV, radio and social media to create a big megaphone for himself, was not silent for long.
In a text to The Associated Press, he responded by referring to his bosses with the F-word and, "They lose," followed by the word "Trolls." Asked if he planned to sue, Sheen texted back, "Big." As for his next move, Sheen texted, "A big one."
A call to his attorney, Marty Singer, seeking comment was not immediately returned Monday. CBS declined to comment.
The firing capped a rare, raging public battle between a Hollywood star and those who employ him, with Sheen claiming the right to live as he pleased - including the acknowledged use of illegal drugs, although he's said he is currently clean - as long as he showed up sober and ready to work.
"Two and a Half Men," which debuted in 2003, stars Sheen as womanizing bachelor Charlie Harper, who creates an ad hoc family with his neurotic brother, the divorced Alan (Jon Cryer) and Alan's son, Jake (Angus T. Jones).
The show was co-created by veteran producer Chuck Lorre, who contributes two other comedies to the top-rated CBS lineup, "The Big Bang Theory" and "Mike & Molly." Like "Men," both are produced with Warner.
Sheen focused many of his attacks on Lorre, and in the end the studio "went with the hit-maker," said media industry analyst Shari Anne Brill.
Several news camera crews were camped out Monday across the street from Sheen's gated neighborhood, Mulholland Estates, in hopes that he'd emerge to discuss his dismissal. A few news helicopters also surveyed the scene from above the Hollywood Hills.
Warner and CBS had long faced a balancing act with Sheen as he underwent rehab and two ugly splits from wives No. 2 (Denise Richards) and No. 3 (Brooke Mueller Sheen). On one side was the wayward star, on the other was TV's most successful and highly lucrative sitcom, anchoring Monday for CBS and making hundreds of millions of dollars for Warner.
Last month, Warner canceled the remaining eight episodes of what was intended to be a 24-episode season of "Men," citing Sheen's public behavior and rants against Lorre.
In a series of interviews, including with ABC's "Good Morning America" and NBC's "Today" show, Sheen boasted about his "epic" partying, said he's fueled by "violent hatred" of his bosses and claimed to have kicked drugs at home in his "Sober Valley Lodge."
He glorified himself as a "rock star from Mars" with "fire breathing fists" and "Adonis DNA" and talked about his home life with two women he nicknamed his "goddesses."
The actor, who was among TV's highest-paid at a reported $1.8 million per episode for "Men," brashly said at one point that he would ask for $3 million if he signed a new contract for future seasons.
There was public fascination with the gloves-off battle. When Sheen added Twitter to the arsenal, he gained 1 million followers in an unprecedentedly brief 25 hours, leading Guinness World Records to establish a new category and crown him the champion. He now has well over 2 million followers.
But Sheen's professional conflict devolved into a custody battle over his 23-month-old twin sons with estranged wife Mueller Sheen. She used his public remarks, as well as conduct she claimed was threatening and violent, to seek a court order removing the children from his home last week.
While Sheen's text to AP suggested his next major role could be that of plaintiff in a lawsuit, the immediate question for Warner and CBS was whether to keep the show alive by bringing in a new cast member to join Cryer and Jones - the one-and-a-half men left.
"They didn't say the show was canceled. They said he was canceled," said analyst Brill. "So the door is still open for another season."
Shows have replaced stars before and lived to fight for ratings another day. When Valerie Harper left "Valerie" after the 1986-87 season in a dispute with producers, the show was renamed "The Hogan Family," Sandy Duncan was brought in to play a new character and the sitcom continued until 1991.
Drew Carey, who starred in and co-created "The Drew Carey Show," was asked about the possibility recently, before Sheen's firing.
"All you have to do is bring in someone you can plug into a Charlie Sheen-like character and deliver those kinds of lines. There are 100 actors who could do it," said Carey, host of "The Price Is Right."
Carey said he wasn't dismissing Sheen's comedic talent and acknowledged that ratings might suffer if viewers are reluctant to accept a new actor in a new role. But Holland Taylor, who plays Sheen's mother, called him "the brand of the show" in an interview last summer.
The studio, however, could save money by paying the substitute far less than Sheen's salary and extend the life of the lucrative series by another season or two.
CBS Corp. Chief Executive Leslie Moonves, interviewed at an investors' conference Monday morning, sidestepped the Sheen controversy when it was brought up by Deutsche Bank analyst Doug Mitchelson.
When Moonves discussed controlling series' costs by making "adjustments," such as "let's say, not renewing some high-priced actors," Mitchelson asked if Moonves had ever successfully replaced a show's lead actor before. Moonves remained silent, and the analyst apologized and said he'd promised "no Charlie Sheen questions."
Despite his troubled personal life, or perhaps because of it, Sheen found an on-screen niche as the bad boy audiences loved, especially in "Two and a Half Men."
But he had an ugly history, with allegations of violence against women, including Mueller Sheen. On Christmas Day 2009 in Aspen, Colo., she told police that Sheen threatened to kill her and brandished a knife after she asked for a divorce. Sheen said they argued but denied threatening her.
In a plea deal, Sheen pleaded guilty to misdemeanor third-degree assault in exchange for the prosecution dropping two more serious charges, and was sentenced to 30 days in a rehabilitation center and 30 days of probation.
CBS is owned by CBS Corp., whose shares were up 6 cents at $23.68 in after-hours trading Monday after closing down 34 cents, or 1.4 percent, at $23.62 in the regular session. Shares of Warner Bros. parent Time Warner Inc. were down a penny at $36.77 in the extended session after losing 47 cents, or 1.3 percent, to close at $36.78.
The market had closed before the statement about Sheen's firing was released by Warner.
AP Entertainment Writers Anthony McCartney and Derrik J. Lang, and AP Business Writer Ryan Nakashima contributed to this report.