Robert George Seale was born on October 22, 1936, to George and Thelma Seale. His father was a master carpenter, and his mother was a home maker. The oldest of three children, Seale grew up with his younger brother Jon, his sister Betty, and his cousin Alvin Turner. Bobby Seale's early life was marked by an abusive father whose job caused times of heavy poverty for the family of five. The family faced four major moves from Dallas, to San Antonio, to Port Arthur, Texas, and finally settled in the Berkeley/Oakland area of California during World War II. Despite these hardships, Seale describes his childhood as typical for black men of the time. Seale attended Berkeley High School in Berkeley, California. During his high school years Seale began to form a political consciousness. He began to question the knowledge he learned in school on issues such as Native American history and the African continent.

Seale enlisted in the United States Air Force in 1955, but was given a bad conduct discharge in 1959 following a run-in with his superior officer. While going to night school at Merritt College in Oakland, California, Seale worked odd jobs, including working as a sheet-metal mechanic (the trade he learned in the Air Force) and a comedian.

In September of 1962, Bobby Seale met Huey P. Newton. A native of Louisiana, Newton had lived in Oakland since the age of three. Newton attended Merritt College, but at the time of their meeting he was attending Oakland City Law School. The two met at a rally protesting the Cuban Blockade. They quickly became friends and political confidants.

In October 1966, Huey P. Newton and Bobby Seale founded the Black Panther Party for Self-Defense. The group would later be renamed the Black Panther Party. The Panthers where originally envisioned as an armed patrol protecting the black community from the racist Oakland Police force. As their reputation grew both locally and nationally, the scope of the organization changed. The Black Panthers disagreed both with the non-violent message of the mainstream Civil Rights movement and the Back-to-Africa theory of the more radical Black Nationalists. Newton and Seale developed a Ten Point plan that became the Party's manifesto. It included the following: the power to black self-determination, universal education and health care, better housing, and community control of industry. A mix of Marxism, Black Nationalism, and the Civil Rights movement, the Black Panther Party offered the next step in the fight for the rights of African Americans. Seale was appointed Chairman of the party, and Newton was made Minister of Defense.

Besides its community outreach programs, the Party organized political issues such as gun reform in California and what they called the U.S Global Wars of Aggression. The party quickly spread, opening chapters in Philadelphia, New York, Boston, Chicago, Newark, Omaha, Denver, New Haven, San Diego, and Los Angeles. Unfortunately, internal strife and the FBI's Counter Intelligence program tore the Black Panther Party apart.

In 1968, Seale wrote Seize the Time: The Story of the Black Panther Party and Huey P. Newton. The book is a first hand account of the history and development of the Black Panther Party. He won the Martin Luther King Memorial Prize for Seize the Time. The same year the book was published, Seale was arrested while protesting at the Democratic National Convention in Chicago. He, along with seven other defendants, were tried in what became known as the case of the Chicago Seven. During the trial, Seale threw barb after contentious barb at both the judge and the court in general, and eventually he was put in prison for being in contempt of court. He was held in prison until 1972 after the trial ended in a hung jury.

After his release, Seale began the job of reorganizing the demoralized and broken party. At the time, the Panthers had spilt into to camps, one supporting Newton and Seale, and one supporting exiled former Party leader Eldridge Cleaver. In an attempt to change the image of the Black Panther Party, Seale ran for mayor of Oakland in 1973, forcing a run-off with Republican incumbent Mayor John Reading. Seale lost to Reading by 70 percent, but his strong showing proved how powerful a voice both he and the Party had become.

Eventually Seale tired of politics. In 1978, he wrote his autobiography: A Lonely Rage: The Autobiography of Bobby Seale. The book traces Seale's life in the narrative form that reader had come to expect from him. The publication of the A Lonely Rage marked the end of Seale's major involvement in politics. However, he continues to develop community-based organizations and is seen on the speaker's circuit.

In 1998, Seale wrote Barbeque'n with Bobby Seale, a cook book that draws from his southern roots. In it, Seale shares traditional marinating recipe and techniques as well as various sauces. 

While living in Philadelphia, Pennsylvania, he served as the community liaison officer for Temple University's Afro-American Studies Department for ten years. He also had roles in the Malcolm X film in 1992 and the film Rude Awakening in 1989. In 2002, Seale returned to live in Oakland in order to further work with younger activists to create social and political change. He refers to himself as a "political revolutionary human-ist." He has been married twice and has two children.