Hilary SwankHilary SwankHilary Swank has some lovely tresses.

But not for much longer.

She's doing something drastic but also v good.

Hils is hacking off her long locks.

We hear that gasp, but let us explain.

It's all for a good cause.

She's having the chop on the Oprah Winfrey Show later this month

But it ain't some telly gimmick... it's actually for charidee.

She's got involved in the Beautiful Lengths charity campaign.

Which is encouraging women and men to whack off their hair and donate it for wigs to aid cancer patients undergoing chemotherapy.

Hils has jumped onboard the charitable train and it's full steam ahead.

She told USA Today: "I've been growing my hair for months, so it's super-long and super-healthy.

"I've gotten my conditioning treatments every four weeks.

"Everyone is commenting on my hair and how it's long and pretty and healthy and shiny.

"All the better for a woman in need."

It's official: we heart Hils.