For most Americans, Christmas comes but once a year — but not for Rosie O’Donnell, who plays Santa year round.

The ENQUIRER has uncovered deeply touching stories of how the star has quietly opened her heart, her home and her wallet to help ailing friends.

“If there really is a Santa Claus, it’s Rosie,” says grateful Jaren Millard, 57, a Hollywood hairdresser and makeup artist whose living expenses were generously paid by the former talk show queen when he became so ill he couldn’t work.

“Not only did Rosie pay my medical bills, but after I was released from the hospital — and had no place to go — she flew me in her own private jet to her Florida home and provided for my round-the-clock nursing care,” he told The ENQUIRER.

“Until the time I was back on my feet and able to care for myself, she continued to help me. If not for her, I would’ve been out on the streets or in a shelter.

“And I knew a hairdresser whom she moved into her home after he was stricken with AIDS. He stayed there — and she paid all his bills — until his death.

“I have also met several women battling breast cancer whom Rosie has helped.”

The generous funnylady does not publicize her good deeds — even the extraordinary ones, like the time she assisted Jason Opsahl, who co-starred with her on Broadway in “Grease.” Jason fell so ill he was no longer able to act — yet he faced mounting medical bills.

Opsahl — who was diagnosed with a brain tumor in 1997 — died this past October 25 at age 39.

Not only did Rosie quietly help pay for his care, but she also gave him money for food and rent after he left the hospital.

Jason’s thankful mom, Muriel Opsahl, told The ENQUIRER:

“Jason had many friends who loved him. But Rosie was a special friend. She even sat with us at the funeral service, like family.”

Millard — who was in the news recently for being in a car crash with Zsa Zsa Gabor — said what makes O’Donnell’s help so special is that it comes from the heart and is given with genuine love.

“Lots of stars are happy to lend their name to or donate money to a cause. They’re happy to have the press coverage, but most don’t want to become personally involved.

“Rosie is not like that. She not only gives the money directly, she also stays in constant touch with you, wanting to know how you are doing. She really cares and doesn’t ask for anything in return.”

The funnylady came to Millard’s rescue on several occasions — and he says she even saved his life.

When he was recuperating from pneumonia in 1997, she flew him from Hollywood to her Miami home where she provided him with skilled round-the-clock nursing care until he could get back on his feet.