Ada Wong (エイダ・ウォン, Eida Won?) is the pseudonym of an enigmatic unnamed Chinese spy. She has gained notoriety in the corporate world for being able to handle serious situations and the most difficult requests without guilt.

Wong has acted secretly in the background of many biohazard incidents and collected information which became useful to several organizations, while at the same time operating to undermine them. However, Wong follows only her own "true purpose".