Abigail Masham, Baroness Masham, was an English courtier. She was a favourite of Queen Anne, and a cousin of Sarah, Duchess of Marlborough.

A favourite was the intimate companion of a ruler or other important person. In post-classical and early-modern Europe, among other times and places, the term was used of individuals delegated significant political power by a ruler. It was especially a phenomenon of the 16th and 17th centuries, when government had become too complex for many hereditary rulers with no great interest in or talent for it, and political institutions were still evolving. From 1600 to 1660 there were particular successions of all-powerful minister-favourites in much of Europe, particularly in Spain, England, France and Sweden.