Hightower is of African-American and Blackfoot descent and grew up in Kilmichael, Mississippi. She grew up in a poor family and worked various odd jobs to help support them. Hightower became a FLIGHT attendant for Trans World Airlines, attracted by the possibility of traveling and expanding her horizons. Settling in Paris and later London, she worked variously as a mutual fund trader and restaurant worker. In 1987, while working at Mr. Chow, an upscale London Chinese restaurant and Celebrity hangout, she met and began dating Robert De Niro.

Hightower and De Niro married in 1997. In 1998, at the age of 42, she gave birth to the couple's first child. The couple's early marital woes were a hot tabloid topic when De Niro filed for divorce in 1999 and sued Hightower for custody of their son in 2001. However, the two worked things out, and by 2004 the divorce was dropped and they renewed their vows. In 2011 the couple had their second child, via surrogate.

As a singer, she performed the lead vocals for the track, "Somethin's Comin' My Way", written by Dan Manjovi for the 2009 Precious movie Soundtrack.

As a socialite, Hightower's gala 55th birthday party was covered in Vogue magazine by André Leon Talley. In 2010, she presented the Pratt Institute's Creative Spirit Award to Director Lee Daniels.

As a philanthropist, Hightower launched "Grace Hightower & Coffees of Rwanda" in 2013 with the mission of improving Rwandan livelihoods by marketing their products internationally. She is a board member of the New York Women's Foundation and the New York Fund for Public Schools as well as a member of Ronald Perelman's Women's Heart Health Advisory Council and the International Women's Coffee Alliance. Hightower has been honored for her work by numerous institutions including the American Cancer Society of New York City.