The troubled actress - who served just 13 days of a 90-day jail term in July for violating the probation terms of a 2007 conviction for driving under influence (DUI) - will be incarcerated until October 22 after failing two court-ordered drugs tests last week.
Despite testing positive for cocaine and amphetamine abuse, it was widely believed Judge Elden Fox would send the 24-year-old actress back to rehab, rather than prison.
However, he made his decision without hearing arguments from lawyers on either side.
Lindsay was said to look "shocked" and glanced at her attorney Shawn Chapman Holley upon hearing the ruling, before being escorted out of the courtroom in handcuffs.
It is also believed the `Mean Girls` star - who arrived at Los Angeles Superior Court with her mother Dina - will have no chance of being released from prison before October 22.
Also in attendance at the hearing was Lindsay`s estranged father Michael, who is legally required to remain at least 100 yards from his ex-wife Dina, and was breaking the law himself by turning up to the courtroom.
Speaking about his daughter`s sentencing outside the courthouse, he said: "Jail is not good for anyone. It doesn`t help to rehabilitate anyone. I`ve been there myself. Lindsay knows what she needs and knows what she wants but unfortunately it`s a little too late.
"She doesn`t belong behind bars. She hasn`t got help for her addictions yet. Leaving Los Angeles and going to New York Fashion Week was the biggest mistake in the world. There are drugs everywhere. She was staying in a hotel unsupervised. She`s hanging around the wrong people in the wrong places. Why is everyone pointing the finger at Lindsay?"
Lindsay spent just 22 days of a 90-day court-ordered rehab stint at the UCLA Medical Centre following her release from prison in August.