Fourth-degree black belt in judo.
At age 17 became youngest judoka (judo player) to compete at the Olympics, during the 2004 games in Athens, Greece.
At the 2008 Olympic Games in Beijing, she won a bronze medal, becoming the first American woman to win a medal since judo's inclusion in the Olympics.
Was given the nickname "The Arm Collector" because she has won all her mixed martial arts bouts by arm bar.
One of her nicknames, "Rowdy", was given to her by retired pro-wrestler "Rowdy" Roddy Piper.
Her mother, Dr. AnnMaria DeMars, is a seventh-degree black belt in judo, and the first American to ever win a world championship in judo, in 1984.
Has two older sisters, Maria Burns-Ortiz and Jennifer Rousey, and one younger sister; Julia DeMars.
Her maternal grandfather, Joseph Arthur Waddell, was the son of immigrants from Trinidad, an island off the northeast coast of Venezuela; his ancestry included African, Spanish, and English, and he was the son of prominent Dr. Alfred Ernest Waddell, who settled in Canada. Ronda's other ancestry is 1/16th Polish, as well as English, German, Scottish, and distant Dutch.
She trains at Glendale Fighting Club under striking coach Edmond Tarverdyan and wrestling coach Juan Martín Berberián. She also trains at Hayestan MMA Academy under Gene LeBell, and Gokor Chivichyan and at Gracie Academy Torrence under Rener Gracie and Ryron Gracie.