The Mean Girls actress was given the term as well as 480 hours of community service by Judge Stephanie Sautner in a Los Angeles court. Testimonies were given against her in the case of a $2,200 necklace she allegedly stole from a top-end boutique and evidence was shown that she had violated her probation stemming from a 2007 driving under the influence (DUI) conviction.
Judge Sautner said: "She is to serve 120 days... forthwith. Perhaps she might see how women who have fallen on real hard times have to live and maybe she will change."
However, Lindsay's lawyer Shawn Chapman said she would appeal the ruling, allowing her to leave the Lynwood Correctional Facility and return to her Venice Beach home after her $75,000 bail was paid.
Her grand theft charge was also downgraded to a misdemeanor by the judge, who said she often sees more serious cases get similarly reduced.
After Kamofie & Co jewellery store owner Sofia Kaman gave her case against the 24-year-old star, Judge Sautner agreed that Lindsay had been "brazen."
She said: "I see the intent here. I see a level of brazenness with, 'Let me see what I can get away with here.'"
However, she said she was giving the actress—who pleaded not guilty in court yesterday (April 22)— "an opportunity" by reducing the charge.
Following the proceedings, Lindsay's father Michael Lohan told RadarOnline.com: "I am not very happy. I don't think her case was handled the right way."
According to the website, district attorney Jeanette Meyers will appeal the judge's decision to reduce Lindsay's charge from a grand theft to a misdemeanor.
She is now set to return to court on May 11 for a pre-trial hearing in her misdemeanor case, with the actual trial planned for June 3.
