Lindsay Lohan has sworn off the City of Angels ... and it's possible she's finally got her head on straight.
LiLo told the Guardian her time in the U.K. has been eye-opening ... and made her realize the L.A. nightlife scene helped trigger her downward spiral -- so she says she'll stay in the U.K. for good.
The 28 year-old says, "I won't live in LA again, hell no."
"I can go for a run here on my own," Lohan explains ... adding, "I do every morning, early, and I think how my friends in New York would still be up partying at that time. I needed to grow up and London is a better place for me to do that than anywhere else.”