The perennially troubled star told judge Stephanie Sautner, whom she has seen repeatedly over the last year or two over a drunk-driving offense and a jewelry theft: "I just want to thank you for being fair.
"What you've done has really opened a lot of doors for me," said the 25-year-old, dressed in a light-blue pantsuit for the brief appearance before the Los Angeles Superior Court judge.
The comments came after the judge said Lohan "has done everything that this court has asked of her," adding that she did not expected to see the actress again, despite leaving one informal probation sentence in place.
"Probation terminates today. Now," she said, adding: "You don't need to come to court anymore."
But the judge warned: "You need to live your life in a more mature way, stop the nightclubbing, and focus on the work," adding: "I know it's hard when people are following you all over the place... but that's the life you chose."
Lohan -- the promising child star of hit Disney movies "The Parent Trap" and "Freaky Friday" -- is well known for her hard partying and has faced a series of legal tangles over the years.
She was sentenced to 35 days of house detention last May as part of a plea bargain over the alleged theft of a $2,500 necklace from a jewelry shop near her home in Venice Beach.
In November, Lohan spent five hours in prison after being sentenced to a 30-day stretch for breaching probation on previous offenses including a 2007 drug and drunk driving misdemeanor.
Her probation terms notably included doing community service at the LA morgue, and undergoing psychotherapy sessions.
In court Thursday, the judge lifted Lohan's probation for the 2007 drunk driving case, and changed her formal probation for the necklace theft into informal probation.
That informal probation term ends in May 2014, but under its terms Lohan does not need to appear in court again as long as she does not commit a new offense.
An alleged hit-and-run incident involving Lohan was noted in her probation report, but there was insufficient evidence for it to pose a problem with ending her formal probation.
"The probationer allegedly hit a car and left the scene. However, no charges have been filed and the probationer has not been arrested. The investigation is still pending," said the probation report, cited by the TMZ celebrity website.
The star was featured in a nude photo spread in the January/February issue of Playboy, for which she was reportedly paid nearly $1 million. Earlier this month she appeared on popular US sketch comedy show "Saturday Night Live."
TMZ reported Thursday that Lohan is due to play Elizabeth Taylor in a film about the late screen legend's stormy relationship with two-time husband Richard Burton.
Lohan's participation in the film, to be shot in Toronto, had been called into question because Canadian authorities can block work permits for applicants with a criminal record.
But TMZ said that obstacle had been overcome, notably due to the star's success in finally complying fully with her probation terms.
She is also expected to appear in an upcoming episode of hit TV show "Glee," according to media reports.