Carmel police said the drugs found in Irsay's vehicle weren't associated with any prescription bottles found inside.
Irsay faces a preliminary misdemeanor charge of driving while intoxicated and four felony counts of possession of a controlled substance, Hamilton County Sheriff's Department Deputy Bryant Orem said.
If convicted on the felony charges, Irsay could face of six months to three years in prison on each count. So-called Schedule IV drugs such as those with which Irsay was allegedly caught include drugs such as Xanax, Darvocet and Ambien, with a low risk for abuse or dependency, according to the Drug Enforcement Agency.
Irsay was being held at the Hamilton County Jail under $22,500 bond.
An NFL spokesman says he is subject to discipline. Myra Borshoff Cook, a spokeswoman for Irsay, declined to comment and Colts spokesman Avis Roper said the team was still gathering details.
"The team will issue additional statements when the facts are sorted and we are aware of the next steps to this process," Roper said. "Many fans have reached out to express their concern and we appreciate their support."
The case has some similarities with that of Detroit Lions president Tom Lewand, who was suspended for 30 days and fined $100,000 in 2010 for violating the NFL's personal conduct policy following his guilty plea to driving while impaired.
Irsay is a popular and colorful figure in Indianapolis, frequently interacting with fans on Twitter about everything from the fortunes of the Colts to his favorite music of the day. He was a key supporter in the drive to bring the Super Bowl to Indianapolis two years ago and he helped build the Colts into an AFC power over the past decade behind quarterback Peyton Manning, now with Denver.
When the Colts were forced into rebuilding mode, Irsay painfully parted with Manning and other veterans, but put together another winning team behind young quarterback Andrew Luck and others.
Irsay wrote an October 2013 tweet saying "I don't drink...haven't in over 15 years." He acknowledged in 2002 that he had become dependent on painkillers after several years of orthopedic operations but said he had overcome the problem after undergoing treatment.
The DEA investigated the case, but local prosecutors at the time said they saw no reason to charge Irsay.
A plastic surgeon who wrote painkiller prescriptions for Irsay surrendered his federal permit to prescribe narcotic drugs but has since regained it. A person who answered the phone at that doctor's office said the physician no longer treats Irsay and a person who answered the phone at the pharmacy where Irsay bought his drugs at that time said Monday that Irsay no longer brings prescriptions there.
Irsay became the Colts owner in 1997 after the death of his father, Robert Irsay and a lengthy legal battle with his father's second wife. Along the way, Jim Irsay held virtually every job from ball boy to general manager. Forbes magazine has estimated Irsay's net worth at $1.6 billion.
Meg Irsay filed in November for divorce from her husband of 33 years, citing an "irretrievable breakdown" of the marriage. Irsay retains full ownership of the Colts and his other business interests. The couple, who married in 1980, had been separated for a decade and are the parents of three adult daughters.
Since taking ownership of the team, Jim Irsay has made a reputation for himself by buying the scroll manuscript of Jack Kerouac's beat poem "On the Road" for $2.43 million. Irsay helped produce "Colors," a tribute to Ryan White, a boy with AIDS whose legal struggle to attend a school in Indiana became a national cause in 1985; White died in 1990 at the age of 18.