The Diocese of Zealand (Danish: Sjællands Stift) was a Lutheran diocese in Denmark that existed from 1537 to 1922. The diocese had been formed in 1537 following the Reformation of Denmark, and was dissolved in 1922 when it was divided into the Diocese of Copenhagen and the Diocese of Roskilde. While it existed, the diocese functioned as the head of the Church of Denmark, beneath the crown, and its bishop was regarded as Primus inter pares.