Anthony Frederick Augustus Sandys, usually known as Frederick Sandys, was a British painter, illustrator and draughtsman, associated with the Pre-Raphaelites. He was also associated with the Norwich School of painters.

Frederick Sandys was born in Norwich, and received his earliest lessons in art from his father, Anthony Sands, who was himself a painter. His early studies show that he had a natural gift for careful and beautiful drawing. He was educated at Norwich School and later attended the Norwich School of Design in 1846. In the same and next year his talent was recognized by the Royal Society of Arts.

In 1862 Sandys met actress Mary Emma Jones, known as Miss Clive, when she modeled for The Magdalen, now owned by the Norwich Castle Museum. A relationship developed between the two; he became devoted to her, taking her as his common-law wife for the rest of his life. She gave birth to a large number of children, 10 of whom were raised under the name of Neville and survived after Sandys' death. She appears in paintings such as Sandys Love's Shadow and his 1867 work Proud Maisie, which was inspired by Mary - so much so that he made at least 11 versions by 1904.

Sandys influenced his younger sister, Emma Sandys (1843–1877), whose works were mainly portraits of children and of young women, often in period or medieval clothing.