Born near Preston in 1799, William Turner went to the English College in Rome in 1820.  He was a fellow student there with Nicholas Wiseman, who later became the first Archbishop of Westminster. Returning to Lancashire in 1826, his ministry encompassed the poor parishes in central Manchester, exploding at that time thanks to the industrial revolution. He was a member of the Old Chapter and became Vicar General to the Bishop of the Lancashire District, Dr Brown.

William Turner was consecrated first Bishop of Salford by Cardinal Wiseman on 25th July 1851.

Bishop Turner had to contend with pressures caused by the Irish potato famine of the 1840s and the American cotton famine of the 1860s. He lost a tenth of his clergy through fever contracted during their service of the sick. Even so, he increased the number of parishes from 30 to 70 during his time of office. He promoted Catholic education at primary and secondary level. He introduced the Xaverian Brothers in 1854 and founded the Salford Catholic Grammar School in 1862. During his episcopate the female teaching orders of Loreto and the Faithful Companions of Jesus also came to the diocese, the Sisters of the Cross and Passion were founded, and with Alice Ingham of Rochdale he laid the foundations for the future Congregation of the Franciscan Missionaries of St Joseph. Bishop Turner attended the first Vatican Council (1869-1870), though ill-health forced him to return to England before the Council ended. He died in office at Salford on 12th July 1872.