Lydia Selina Dunn, Baroness Dunn, is a Hong Kong-born retired British businesswoman and politician. She became the second person of Hong Kong origin and the first female ethnic Chinese Hongkonger to be elevated to the peerage as a life peeress with the title and style of Baroness in 1990.

The Senior Unofficial Member, later Senior Member and, finally, Convenor of the Non-official Members, was the highest-ranking unofficial member of the Legislative Council (LegCo) and Executive Council (ExCo) of British Hong Kong, which was tasked with representing the opinions of all unofficial members of the council to the Governor.