Born in Brooklyn, she attended Yale University and completed a Juris Doctor degree at Duke University in 1979. A resident of the Atlanta suburb of Stone Mountain since 1983, Majette was appointed by Governor Zell Miller to the State Court of DeKalb County in 1993.

She resigned from the judgeship in 2002 to run for the U.S. House of Representatives in Georgia's 4th congressional district, which was based in DeKalb County. In a major upset, she defeated 10-year incumbent Cynthia McKinney in the Democratic primary. McKinney had attracted controversy due to her comments after the September 11, 2001 attacks and her reported backing by Palestinian groups. It was stunning enough that Majette, who had never run in a partisan contest before, was able to defeat the seemingly entrenched McKinney. However, Majette trounced McKinney by 16 points. Majette's upset win was tantamount to election in the heavily Democratic district.

Majette would have likely been able to keep her congressional seat for as long as she wanted, given the 4th's heavy Democratic tilt (only the neighboring Atlanta-based 5th is considered more Democratic). However, after only one term, she decided to run for the U.S. Senate seat being vacated by Miller, who had been appointed to the seat in 2000 to replace the late Republican Paul Coverdell. Miller's decision not to seek a full term in the Senate had caught the Georgia Democrats by surprise, and Majette was the first Democrat to enter the race who was thought to have a realistic chance of keeping the seat in Democratic hands. She finished just short of winning the nomination outright, but easily won the runoff. Majette faced Republican 6th District Congressman Johnny Isakson in the general election on November 2, 2004, and was heavily defeated, losing by almost 16 points.

A number of factors led to the severe defeat. Majette had to spend valuable time and money in the runoff; in contrast, Isakson had won the Republican nomination by a surprisingly large margin. Due to her late entry in the race, she had little time or chance to make up ground on Isakson. A proposed constitutional amendment banning same-sex marriages boosted Republican turnout significantly; it carried in every county, even DeKalb. In addition, John Kerry had effectively ceded Georgia to George W. Bush early in the presidential campaign. Despite the loss, Majette became both the first African-American and the first woman to be nominated for the U.S. Senate in Georgia.

McKinney regained her seat in the 2004 election. While McKinney had made no secret that she wanted her old seat back, it is not known whether Majette's decision to run for the Senate was related to a possible rematch against McKinney.

Soon after leaving the House, Majette entered private law practice in Atlanta. In March of 2006, Majette announced her candidacy for State School Superintendent of Georgia. If she wins in the primary, she will face Republican incumbent Kathy Cox.