Marilyn Jean Hartman, 62, was released from the Century Regional Detention Facility in Lynwood, California, shortly after 6 p.m., according to jail records.
She was released because of jail overcrowding and a state program that credits nonviolent misdemeanor offenders such as Hartman for good behavior, time served and other circumstances, Los Angeles County Sheriff's Deputy Crystal Hernandez said.
A court commissioner ordered Hartman on Wednesday to serve jail time for wandering around LAX on Aug. 7, a day after being ordered to stay away from the airport.
Hartman, who has made previous attempts to sneak aboard flights at other airports, was arrested Aug. 4 for taking a Southwest Airlines flight from San Jose to Los Angeles without a ticket. Her boarding status was discovered once the plane landed in Los Angeles.
At Mineta San Jose International Airport, Hartman tried at least three times to get to a plane before she finally went past a security screener who was busy checking a family's documents, law enforcement officials said.
She later pleaded no contest to a misdemeanor count of willfully and unlawfully entering Los Angeles as a stowaway on an aircraft and was sentenced to two years of probation.
In February, Hartman was sentenced to 18 months' probation in San Mateo County after being arrested for attempting to board three Hawaii-bound flights at San Francisco International Airport on three separate days.