On February 3, 1889, two days before her 41st birthday, she was ambushed and killed while riding home from a neighbor's house in Eufaula, Oklahoma. According to legend, she was shot with her own double barrel shotgun. Suspects included her new husband and both of her children, but the case was never solved.

Eddie Reed, Belle's son, was convicted of horse theft and sent to prison in July 1889. Rosie Reed, Belle's daughter, also known as Pearl Starr, became a prostitute to raise funds for Eddie's release. She eventually obtained a presidential pardon in 1893. Eddie became a deputy in Fort Smith and killed two outlaw brothers named Crittenden in 1895. He was himself killed in a saloon in Claremore, Oklahoma on December 14, 1896.

Although she was relatively unknown outside Texas for most of her life, Belle's story was picked up by National Police Gazette publisher Richard K. Fox, who made her name famous with his dime novel Bella Starr, the Bandit Queen, or the Female Jesse James, which he published in 1889 (the year of her murder). This novel is still cited as a historical reference and was the first of many popular stories that used her name.

Belle Starr (1941) featured Gene Tierney as Belle and Randolph Scott as Sam Starr. It was the fourth film to portray Belle on the silver screen, but it was the first major Hollywood production to do so. Its success led to many more such portrayals.

In "Belle Starr", Woody Guthrie sings:
"Belle Starr, Belle Starr, tell me where you have gone
Since old Oklahoma's sandhills you did roam?
Is it Heaven's wide streets that you're tying your reins
Or singlefooting somewhere below?"