This makes her the first female Ghanaian-British MP in the UK.
She is following in the footsteps of her male colleagues Adam Afriyie, Sam Philip Gyimah, and Kwasi Alfred Addo Kwarteng.
The Labour Party candidate polled 19,882 votes to beat Joe Robertson of the Tory Party, who received 16,124 votes.
The Erith and Thamesmead seat has long been a stronghold of the Labour Party.
Longtime MP Teresa Pearce stepped down before this election, making way for Abena Oppong-Asare to succeed her.
Abena Oppong-Asare is a former Bexley councillor who served as a ward representative for four years until 2018.