The 28-year-old actress was reportedly caught having sex in public during daylight last month. She later claimed that she was detained by police because of her skin colour.
The Los Angeles Police Department responded to the allegations of racism, saying that the actress made "malicious and false statements."
Watts - who played CoCo in Quentin Tarantino's 2012 film - and her boyfriend Brian James Lucas have now been charged with lewd conduct, a misdemeanor conduct charge that could result in six months in county jail and a USD 1,000 fine, TMZ reported.
The star had initially claimed that the incident was racially charged, because she is black and her boyfriend is white.