Johan Tobias Sergel was born in Sweden on 7 September 1740, at Stockholm. He was the son of the decorator, Christoffer Sergel and Elisabet (née Swyrner), and was the brother of the decorator, Anna Brita Sergel. His first teacher was Pierre Hubert Larchevêsque. After studying for some time in Paris, he went to Rome.
He remained in Rome for twelve years and sculpted a number of groups in marble. Besides subjects from classical mythology such as the 'Diomedes Stealing the Palladium', which he sold to the British collector, Thomas Mansel Talbot, in 1772, he also sculpted a colossal representation of "The Muse of History Recording the Deeds of Gustavus Adolphus," in which are depicted the achievements of Gustav II Adolf before the Chancellor Oxenstierna. It was in Rome also that he modelled the statue of Gustav III, subsequently cast in bronze and purchased by the city of Stockholm in 1796. While primarily a sculptor, Sergel (inspired by English artists like Thomas Rowlandson) also drew several sequential picture stories, considered by many as one of the early forms of comics.
Summoned by Gustav III, Sergel returned to Stockholm in 1779 and continued to produce his works there. Among them are a tomb for Gustav Vasa, a monument to Descartes, and a large relief in the church of St. Clarens in Stockholm, representing the Resurrection. He was an important part of the artistic elite in Stockholm and had a relationship with the celebrated actress Fredrique Löwen and was possibly the father of one of her children. He died in his native city on 26 February 1814.