Gemma Jackson (born 1951) is an English production designer and art director. She has spent the bulk of her career in film, having worked on films such as A Far Off Place, The Borrowers, Bridget Jones’s Diary, and Finding Neverland, for which she was nominated for an Oscar. More recently she won an Emmy for her work on the HBO miniseries John Adams.
Jackson was the production designer on Game of Thrones for Season 1, Season 2, and Season 3. She was faced with the difficult task of physically realizing the small details of the locations in George R.R. Martin's A Song of Ice and Fire novels. Jackson was responsible for designing, building, and dressing the actual physical sets that need to be used in filming the series.
Gemma Jackson left working on Game of Thrones after Season 3, and was replaced as the production designer for Season 4 by Deborah Riley. Jackson explained in the DVD commentary for Season 3 episode 3, "Walk of Punishment" that she left working on the series because it was taking a severe toll on her marriage and personal life to work on such a massive project (a nearly year-round production schedule, coordinating set construction in three to four separate countries at a time).