Tong was educated at St. Michael's School and St. Joseph's Institution. Tong read law at the National University of Singapore, graduating in 1994. After admission to the Singapore Bar, Edwin joined Allen & Gledhill LLP where he is now a partner. He is a Roman Catholic.
His political involvement commenced with grassroots work with various incumbent members of parliament and constituencies, especially the now defunct Jalan Besar GRC. Tong was fielded by the People's Action Party as a candidate in the group representation constituency of the newly formed Moulmein-Kallang GRC. He was elected, with the team garnering 44, 828 votes or 58.56% of the total votes cast. Tong currently serves as a member of parliament for the sub electoral division of Jalan Besar.