For straphangers, this was a cat out of hell.

A runaway kitty caused rush-hour subway delays of up to 40 minutes for 10,000 commuters when he broke free from his owner’s grip and jumped onto a downtown station’s tracks, officials said.

A total of 83 trains were stopped or rerouted along five lines while MTA workers and cops scrambled to get the black kitten out of harm’s way on Wednesday evening.

The cat, named George, was being held on a leash by Mila Rusafova, 23, as she waited for an uptown train with a second cat in a pet carrier at the Canal Street station shortly after 5 p.m.

The Washington Heights woman thought it wouldn’t be a problem to keep George out of a crate in the subway during a trip to the vet.

“He’s a super-chill cat,” she said.

But he quickly turned into a scaredy cat when the E train rumbled into the station — breaking free and leaping onto the rail bed, dangerously close to the third rail.

“He went into one of those rectangular cutouts in the wall,” she said. “He just curled into the corner and was just staring at the wall. He didn’t move.”

Rusafova flagged down the train’s operator with other straphangers and got her to stop before reaching George’s hiding spot.

MTA officials cut power on the line between the World Trade Center and Canal Street — and all of the passengers were taken off the train.

E trains were stalled for more than half an hour, while C trains were forced to run up Sixth Avenue, disrupting the usual flow of B, D and F trains.

Two cops eventually got onto the tracks and snagged the terrified kitty.

“I went over and grabbed him and gave him a little scratch on the head and said it was all good,” said Officer Brian Kenny. “The cat actually put his paws out on each of my shoulders like he was hugging me.”

The MTA used the incident to encourage riders to transport pets in secure carriers.

Rusafova agreed.

“I know that it was foolish that I didn’t have him in a carrier,” she said.