A 30-year-old man was fatally stabbed during a brawl on a Bronx subway Saturday afternoon, police and sources told The Post.

The victim and a 36-year-old career criminal got into an argument at about 3:20 p.m. at the 3rd Avenue–E. 149th Street subway station in the South Bronx, police said.

During the altercation, the 36-year-old stabbed the 30-year-old in the chest with a knife.

According to police sources, the victim was taken to Lincoln Hospital where he was pronounced dead.

His name will not be released until his family is notified, police said.

The 36-year-old was arrested at the subway station.

The suspect has been arrested nine times, including for an attempted rape in Brooklyn in 2009, police sources said. Armed with a knife, he kicked in a woman’s door and punched her in the face before sexually assaulting her, sources said.

According to sources, the suspected stabber brandished a knife during a verbal argument in Brooklyn in 2017 and chased the victim for several blocks.

Saturday’s fatal incident is the latest in a series of stabbings on the subway in the Big Apple.

On Tuesday, a maniac stabbed a 52-year-old man waiting for a northbound 6 train on the platform at East 96th Street and Lexington Avenue at around 3:30 a.m.

The attacker approached the victim and began arguing before stabbing him in the neck with an unknown object, police said. The man was taken to Weill Cornell Medical Center in stable condition; no arrests were made.

On Monday evening, an assailant armed with a box cutter wounded a 29-year-old man in the arm during an altercation on the southbound Line 4 subway at the Brooklyn Bridge-City Hall station, police and sources reported.

The victim was taken to Bellevue Hospital in stable condition. The suspect was not arrested.

A 66-year-old grandmother was found stabbed to death in her Brooklyn home on Tuesday.

Claudette Jones, a nurse, was found with multiple stab wounds in her two-story Cape home on East 56th Street in Flatbush. Her killer is still a mystery.