O'Connor took only two years to complete law school and met her future husband, John Jay O'Connor, while in law school. O'Connor faced a difficult job market after leaving Stanford. No law firm in California wanted to hire her and only one offered her a position as a legal secretary. O'Connor turned to public service and accepted a job as the deputy county attorney for San Mateo, California. When O'Connor's husband graduated from Stanford a year later, the Army immediately drafted him into the Judge Advocate General Corps and stationed him in Frankfurt, Germany. While there, Sandra served as a civilian lawyer in the Quartermaster's Corps. When the O'Connors returned to the U.S. in 1957, they settled in Phoenix, Arizona and had their three sons in the six years that followed.
O'Connor again found it difficult to obtain a position with any law firm so she decided to start her own firm with a single partner. She practiced a wide variety of small cases in her early days as a lawyer since she lacked specialization and an established reputation. After she gave birth to her second son, O'Connor withdrew from work temporarily to care for her children and became involved in many volunteer activities. After five years as a full-time mother, O'Connor returned to work as an assistant state attorney general in Arizona. When a state senator resigned to take an appointment in Washington D.C., Arizona Gov. Jack Williams appointed O'Connor to occupy the vacant seat. O'Connor successfully defended her senate position for two more terms and eventually became the majority leader, a first for women anywhere in the U.S. In 1974, O'Connor decided to shift gears and run for a judgeship on the Maricopa County Superior Court. A year later, the newly elected Democratic governor nominated O'Connor to the Arizona Court of Appeals. Not quite two years later, President Reagan nominated her as the first woman to Supreme Court as a replacement for the retiring Justice Potter Stewart.
Early in her tenure on the Court, most observers identified O'Connor as part of the Court's conservative faction. However, after a few terms, O'Connor established her own unique position on the Court. Although she commonly sided with the conservatives, O'Connor would frequently author a concurrence that sought to narrow the scope of the majority's opinion. She approached each case with individual treatment and always sought to arrive at a practical conclusion. Her moderation has helped her role as the centrist coalition-builder, which consequently enhanced her influence on the Court. She retired from the Supreme Court in 2006.