The offense is punishable by up to five years in prison and a $250,000 fine, although federal sentencing guidelines most likely would call for less. Vick's plea hearing is Aug. 27.
Lead defense attorney Billy Martin said Vick reached an agreement with federal prosecutors after consulting with his family over the weekend.
"Mr. Vick has agreed to enter a plea of guilty to those charges and to accept full responsibility for his actions and the mistakes he has made," Martin said in a statement. "Michael wishes to apologize again to everyone who has been hurt by this matter."
Martin later told The Associated Press he could not divulge any specifics of the plea agreement or how much time Vick can expect to serve in prison.
NFL commissioner Roger Goodell has barred Vick from the Falcons' training camp but has withheld further action while the league conducts its own investigation.
"We totally condemn the conduct outlined in the charges, which is inconsistent with what Michael Vick previously told both our office and the Falcons," the league said in a statement. The NFL added that it has asked the Falcons "to continue to refrain from taking action pending a decision by the commissioner."
Martin said salvaging Vick's NFL career was never part of the discussions.
"Football is not the most important thing in Michael Vick's life," he said. "He wants to get his life back on track."
Vick is charged with conspiracy to travel in interstate commerce in aid of unlawful activities and conspiracy to sponsor a dog in an animal fighting venture. He had pleaded not guilty last month and vowed to clear his name at a November trial.
Martin's announcement came as a grand jury that could add new charges met in private. Prosecutors had said that a superseding indictment was in the works, but Vick's plea most likely means he will not face additional charges.
"I don't blame prosecutors for taking the deal," said CBS News legal analyst Andrew Cohen. "They get to avoid the cost of a long-trial, they get swift sentences for Vick and all the other defendants and they get to focus their energies on other investigations. For the feds, it's a win-win—they held all the cards and played their hand well and this is complete surrender by Vick and the others."
U.S. District Judge Henry Hudson said Vick is not scheduled to visit the courthouse before his hearing next week.
Three of Vick's original co-defendants already have pleaded guilty and agreed to testify against him if the case went to trial. Quanis Phillips of Atlanta and Purnell Peace of Virginia Beach signed statements saying the 27-year-old quarterback participated in executing at least eight underperforming dogs by various means, including drowning and hanging.
In a telephone interview with the AP, Martin said Vick is paying a high price for allowing old friends to influence his behavior, but he emphasized that his client takes full responsibility.
"There were some judgment issues in terms of people he was associating with," Martin said. "He realized this is very serious, and he decided to plead so he can begin the healing process."
Phillips, Peace and Tony Taylor, who pleaded guilty last month, also said Vick provided virtually all of the gambling and operating funds for his "Bad Newz Kennels" operation in rural Virginia, not far from Vick's hometown of Newport News.
Gambling is taboo for NFL players, reports CBS News correspondent Mark Strassmann. Players caught betting potentially face a lifetime ban.
"Vick almost certainly will spend some time in prison—a year or so is my guess—and I would not be surprised if there also are stringent probation requirements, including even some sort of home detention like Martha Stewart had," Cohen said. "And of course all the while Vick's career on and off the field is pretty much on hold."
Vick's Atlanta attorney, Daniel Meachum, told the AP that Vick is taking a chance with his guilty plea as far as his career is concerned because there have been no discussions with the league in recent days.
"There's no promise or even a request of the league to make a promise," Meachum said.
Meachum said the plea deal involves only the federal case. He said he doesn't know if there have been any discussions about resolving Virginia state charges that may be brought against Vick.
The case began April 25 when investigators conducting a drug search at a massive home Vick built in Surry County found 66 dogs, some of them injured, and items typically used in dogfighting. They included a "rape stand" that holds aggressive dogs in place for mating and a "breakstick" used to pry open a dog's mouth.
Vick contended he knew nothing about a dogfighting operation at the home, where one of his cousins lived, and said he rarely visited. The former Virginia Tech star also blamed friends and family members for taking advantage of his generosity and pledged to be more scrupulous.
The July 17 indictment said dogs that lost fights or fared poorly in test fights were sometimes executed by hanging, electrocution or other brutal means. The grisly details fueled public protests against Vick and cost him some of his lucrative endorsement deals.
About a dozen bright red Vick jerseys have been donated — often accompanied by financial contributions — to the Atlanta Humane Society since he was indicted last month. The shelter uses them for dog blankets, and to clean up after the animals.
"Kind of appropriate," said Wayne Pacelle, president of the Humane Society of the United States.