The story is based on a real-life couple, Richard and Mildred Loving, who were arrested in Virginia, US, five weeks after their wedding in 1958, when inter-racial marriage was still banned in the state.
They challenged - and changed - the US's last remaining segregation laws, People Magazine explains.
As for the actress herself, Ms Negga was seven when her Ethiopian father died in a car accident. She was raised by her Irish mother, a nurse, and they moved around before settling in Dublin, reports The Guardian.
Ms Negga is up against Meryl Streep for her performance in Florence Foster Jenkins and Natalie Portman for her portrayal of Jackie Kenedy.