William II (or III) (late 980s – 1019), called the Pious, was the Count of Provence.

[1] William appears in the documents of his father from 992,[2] and succeeded the elder William on the latter's retirement to a monastery just before his death in 994,[3] but as a minor he fell under the control of his paternal uncle, Rotbold I, who would intervene with William and his mother, Adelaide, until Rotbold's death in 1008.

[3] By 1013, he had married Gerberga, daughter of Otto-William, Count of Burgundy and Ermentrude, Countess of Mâcon and Besançon.

[2] Due to his relative youth, throughout his rule William faced challenges from the Provençal lords, including the seizing of his family's ecclesiastical interests.

These conflicts escalated until William died 4 March 1019, while fighting the castellans of Fos and Hyères, and the two widows, Adelaide and Gerberga, were forced to call on the assistance of Adelaide's older son, William III, Count of Toulouse, to protect the birthright of the young heirs.