Parks, 92, died in her sleep at her home in Detroit, said Parks' lawyer, Shirley Kaigler. She had been suffering from dementia and rarely appeared in public in recent years.
Parks, known as the mother of the modern civil rights movement, was a 42-year-old seamstress for the Montgomery Fair department store when she caught a bus in downtown Montgomery, Alabama, on December 1, 1955.
She paid the 10-cent fare in front, then reboarded the bus in back as black riders were required to do, taking a seat in the first row of the section reserved for "coloureds."
Three stops after she got on, a white man boarded and had to stand. To make room for him to sit alone, as the rules required, driver James Blake told Parks and three other black riders, "You all better make it light on yourselves and let me have those seats."
The other riders complied. Parks did not.
"No I'm tired of being treated like a second-class citizen," she told Blake. Blake called police, who asked Parks why she didn't move: "I didn't think I should have to. I paid my fare like everybody else."
Parks was not the first black Montgomery bus rider to be arrested for failing to give up a seat, but she was the first to challenge the law. For years before her arrest, Parks and her husband had been active with local civil rights groups, who were looking for a test case to fight the city's segregation laws.
Four days later, she was convicted of breaking the law and fined $10, along with $4 in court costs. That same day, black residents began a boycott of the bus system, led by a then-unknown Rev. Martin Luther King Jr.
The boycott lasted 381 days, and the legal challenges led to a US Supreme Court decision that forced Montgomery to desegregate its bus system and put an end to "Jim Crow" laws separating blacks and whites at public facilities throughout the South.
Born Rosa Louise McCauley on February 4, 1913, in Tuskegee, Alabama, Parks was raised by her mother, Louisa, a school teacher. her father left the family when she was young.
Her impoverished family moved to her grandfather's farm, which had been part of a plantation. By age 6, Rosa was splitting her days between school and picking cotton on the farm.
She and other children who walked to school were sometimes taunted by white students who threw trash at them out the window of their bus.
When Parks later attended school in Montgomery, she said she grew weary of being told where she could not drink, could not sit, or could not go to the bathroom.
She married Raymond Parks, a barber, when she was 20, and the two became active in the National Association for the Advancement of Coloured People. She was elected secretary of its Montgomery branch in 1943.
Parks' refusal to give up her seat came about a year after the US Supreme Court declared that separate schools for blacks and whites were unequal in the landmark Brown vs. Board of Education case.
She said years later that her refusal, which set a precedent for dozens of other protests against segregation throughout the South, was undertaken with respect for authority.
"I actually did not show disrespect because I did not have any argument, or disorderly conduct, and I did not resist arrest," she said.
For the rest of her life, Parks renounced violence, and urged young people to protest discrimination within the boundary of the law.
"It is better for them to have behaviour that is above reproach and face whatever it is in a way that they can be respected for their actions," she said in an interview several years ago.
Parks and her husband moved to Detroit in 1957, after she lost her job and received numerous death threats in Alabama. From 1965 to 1988, she worked as an aide to US Rep. John Conyers, a Michigan Democrat and founding member of the Congressional Black Caucus.
She became something of a patron saint for the city, which called her "Mrs Parks," with schools and a street named after her. Her husband, Raymond, died in 1977. The couple had no children and Parks' closest living relatives are her brother's 13 sons and daughters.
The city was shocked in 1994 when a black man kicked down the back door of her home, struck Parks in the face several times and fled with $53. The man later told police he stole the money to buy crack cocaine, and did not recognise who his victim was until he was inside the house.
"Many gains have been made, but as you can see at this time, we still have a long way to go," Parks said at the time. "So many of our young people are going astray."
After retirement, she devoted time to the Rosa and Raymond Parks Institute for Self Development, which promotes leadership and civil rights awareness among Detroit youth.
Parks received the highest US civilian honour, the Presidential Medal of Freedom, in 1996 and Congressional Gold Medal of Honour in 1999. Recommending the medal for Parks that year, the US Senate described her as "a living icon for freedom in America."
Former President Bill Clinton recognised her during a State of the Union speech by observing that for most Americans alive today, the struggle against segregation began in the South "when a woman called Rosa Parks sat down on a bus in Alabama and wouldn't get up."
In 2002, the Montgomery bus believed to be the one she was arrested on was sold to The Henry Ford museum in Dearborn, Michigan, for $492,000. Blake, the driver, died in March 2002.