Although the Terminator star rarely gives insight into his current relationship with Los Angeles-based physical therapist Heather Milligan, once in a while he can't help but gush about their enduring romance.
While promoting his new motivational book Be Useful, he opened up about what a positive influence Heather has been in his life.
Arnold, 76, and his girlfriend, 48, first met back in 2012, in the wake of his shoulder surgery and as he was preparing to film Escape Plan with fellow action hero legend Sylvester Stallone, which premiered in 2013.
In a new interview with People, Arnold recalled how his surgeon enthusiastically recommended Heather for his shoulder recovery, and remembered hearing from him: "There's only one [person], it's Heather – any athlete, I always send them to her, because she's the only one that really knows what they're talking about."
He continued: "So I went to her, and then after my therapy was finished, after I was finished with the movie, I called her back and took her out for lunch to say thank you," endearingly adding: "And then one thing led to the next."
Today Heather runs one of the largest physical therapy clinics on the West Side of Los Angeles, Elite OrthoSport, and former bodybuilder Arnold couldn't be prouder.
Gushing about his partner of ten years to the outlet, he described her as "fantastic," and noted: "I think the world of her."
"We have so many things in common," he further shared, adding: "I love that she's into working. She's clearly independent. She just is driven as hell."
Giving further insight into Heather's character, Arnold also revealed she recently came back from Nebraska, where she was taking care of her grandmother.
He said: "Every night, she's with her grandmother on the phone for at least a half an hour," adding: "I mean, that's when you get to know a person, the heart they have."
Arnold finalized his divorce from veteran TV journalist Maria in 2021, ten years after she first filed following the revelation that he had fathered a son, Joseph Baena, 25, with their family nanny, Mildred Baena.
The former couple share kids Katherine, 33, Christina, 32, Patrick, 30, and Christopher, 26, plus they are doting grandparents to Katherine's two kids with Marvel star Chris Pratt, Lyla, 3, and Eloise, 16 months.
Get the lowdown on the biggest, hottest celebrity news, features and profiles coming out of the U.S. Sign up to our HELLO! Hollywood newsletterand get them delivered straight to your inbox.