Tiger's ex, Erica Herman, recently dropped the $30 million lawsuit she filed against his trust ... this according to new court documents obtained by The New York Post.

Erica's decision to drop the suit comes on the heels of a related legal win for Tiger ... as we reported in May, a judge ordered the case to arbitration, which is what Woods wanted.

Tiger's ex originally filed suit against his trust back in March, alleging he wrongly kicked her out of the Florida mansion they lived in together.

Remember ... Erica claimed she was living with Tiger in his Hobe Sound estate for 6 years while they were dating, with Erica claiming she performed "valuable services" for Tiger in exchange for living rent-free.

Erica claimed they had an "oral tenancy agreement" which was supposed to last 5 years after their 2022 split ... but admitted she didn't have it in writing.

She sued Tiger's trust -- the titleholder on the house -- for $30 mil because she claimed it was the "reasonable rental value" of Tiger's house for the 5 remaining years on their alleged oral agreement.

When Tiger and Erica broke up in the fall of 2022, she claims Tiger cooked up a scheme to throw her out of the home, including alleged false promises and a spontaneous vacation.

She claimed Tiger's people convinced her to pack a suitcase for a vacation without Tiger, allegedly driving her to the airport, where they allegedly told her she'd been "locked out" of the house and couldn't go back.