Knicks fans are wearing their heart on their sleeves.

“Basketball psychos” across the Big Apple have been memorializing the team’s historic playoff run by getting tattoos of Knicks players, logo and other iconography permanently etched on their skin.

One blue and orange fanatic, Craig Stevens, branded himself Friday with the 90s version of the Knicks’ logo — a massive tattoo he got on his left arm below his elbow.

To commemorate the occasion, the team’s superfan donned a black Knicks cap and T-shirt featuring Jalen Brunson.

“I loved this team and supported it for my entire life, so it should be part of my body,” said Stevens, 37, a producer and JD, saying his love for the team started in the “womb.”

Stevens had been considering for years undergoing the painful process, which took hours to complete, but finally pulled the trigger this week ahead of the NBA Finals — the first the Knicks will play in since 1999.

“They’re doing so well, and I want to be a part of it that way — showing it,” he told The Post as the needle punctured his skin at Live by the Sword’s Union Square location.

The tattoo will be the only new piece of fan gear Stevens will wear when he watches his team take the court Wednesday from a massive watch party at Pig Beach in Astoria.

“I’m going to be in my same seat that I’ve had, the same jersey that I haven’t gotten washed since the playoffs started, because I’m a lunatic. New York fans are all basketball psychos, all of us,” he said.

Elsewhere in Manhattan, another lifelong Knicks fan of the same surname — but of no relation — was also getting inked with the team’s logo.

Mike Stevens, the manager of Red Rocket Tattoo NYC, has not only been inking plenty of Knicks fans in recent weeks, but he even got one of himself.

“The last time the Knicks were in the finals, I wasn’t old enough to get a tattoo!” said Mike Stevens, 40.

Mike Stevens, whose shop lies just five blocks from Madison Square Garden, was inked Friday by artist Shannon Ritchie with the team’s orange and blue logo — which he said represented the “spirit” of the Big Apple.

His shop has been doling out plenty of similar tattoos in recent weeks, which he’s been offering at discounted prices to meet the moment.

“I’ve been a Knicks fan since I was a kid, but this is probably one of the years since the 90s that there’s been any actual optimism. I’ll celebrate them in every way that I can,” he said.

Even if the Knicks let the championship slip through their fingers, Mike Stevens says he won’t regret getting the logo permanently etched into his skin.

“I’ve sat through some of the worst games of my life and I’ve still cheered for them. I’ll cheer for them through anything, man. There’s no regret, no matter what. They could lose the rest of my life and I’ll still like this tattoo,” he said.

“The logo is always going to be there. It’s always going to be New York. It’s always going to be the Knicks.”

Jay L. of Hello Ink in Dumbo designed a series of Knicks- and Big Apple-themed flash tattoos — which are a smaller and less expensive form of tattoo — in honor of the team. She was shocked to have appointments booked up from superfans looking to fly in from other states to get a slice of the memorabilia.

“It’s the loyalty and the community that New York has built over these years. I don’t think I’ve seen this much loyalty — maybe other than like the Philly Eagles! The environment that people build is definitely none other. You don’t see it in a lot of places,” said Jay L., 29, of Bensunhurst.

Julia Datton-Brush shared the same sentiment while getting her own version of the Knicks logo — alongside one of the Mets — behind her ear at First Class Tattoos on Canal Street.

“There’s something about the energy right now, it’s so good,” Datton-Brush, 46, said, describing herself as a “die-hard fan.”

“It’s a full pride thing … Sports always unify the city.”

— Additional reporting by Fenix Suriel