A Harvard University football player was arrested with viral sorority girl Lily Stewart over the weekend … after cops say they were wandering around a campus building after business hours.

Junior Crimson tight end Seamus Gilmartin and two others were busted alongside Stewart on University of Georgia property around 3 AM Sunday morning … after cops responded to an intrusion alarm at the student center, which closes at midnight.

According to a police report, the group seemingly tried to flee the scene after they noticed the cop approach the building … but once the officer tracked them down, he ordered Gilmartin to comply — which he did.

The report states while 20-year-old Gilmartin was detained, two IDs were found on him — one from New York and another from California. The IDs produced no returns, and both were deemed fakes.

The athlete was charged with underage possession of alcohol, loitering/prowling and possession of a fraudulent ID. On top of that, he is barred from the campus for two years.

Gilmartin’s mug shot might not go as viral as Stewart’s … as the UGA sorority member caused quite the stir after being arrested for speeding earlier this month after being clocked at 84 MPH in a 55 zone.

The 20-year-old was grinning from ear to ear when she posed for the cop cams … and she told us that she’s received dozens of DMs from dudes over it.

With her most recent run-in, Stewart was busted for loitering/prowling and obstruction of a law enforcement officer. According to the report, Stewart claimed she fled because she was out on bond.