Born Carl Ludvig Eugén Bernadotte in the Royal Palace in Stockholm, he was the eldest son of King Oscar I of Sweden and Norway, and Josephine of Leuchtenberg. On June 19, 1851 he married Louise of Orange-Nassau, daughter of Prince Frederick of the Netherlands.

Created Duke of Scania at birth, the Crown Prince was Prime Minister of Norway briefly in 1856 and 1857. He became regent on September 25, 1857, and king on the death of his father on July 8, 1859. As Crown Prince, Charles's brusque and downright manners had led many to regard his future accession with some apprehension, yet he proved to be one of the most popular of Scandinavian kings and a constitutional ruler in the best sense of the word.

His reign was remarkable for its manifold and far-reaching reforms. Sweden's existing communal law (1862), ecclesiastical law (1863) and criminal law (1864) were enacted appropriately enough under the direction of a king whose motto was: Land skall med lag byggas - "Land shall be built upon laws". Charles also materially assisted Louis de Geer to carry through his memorable reform of the Riksdag in 1866.

Charles was a warm advocate of Scandinavianism and the political solidarity of the three northern kingdoms, and his warm friendship for Frederick VII of Denmark, it is said, led him to give half promises of help to Denmark on the eve of the war of 1864, which, in the circumstances, were perhaps misleading and unjustifiable. In view, however, of the unpreparedness of the Swedish army and the difficulties of the situation, Charles was forced to observe a strict neutrality. He died at Malmö.