As a younger son of an earl, he was part of a large group that entered the Church of England, in substantial numbers, where they were "rewarded by generous preferment which made them financially independent of their elder brothers." From 1743 until 1773, Rev. Sherard served as Rector of Wistow in Huntingdon, and of Teigh in Rutland. He also served as Canon Residentiary of Salisbury from 1757 to 1773 and Prebendary of Southwell from 1761 to 1778. In the 1780s, he had three churches built at Teigh, Stapleford and Saxby. On 23 February 1770, upon the death of his older brother, who had married four times but was without surviving male heir, he inherited the earldom of Harborough and the family residence, Stapleford Park. Although he gradually relinquished his clerical preferments, he never resigned his Holy Orders. Around 1772, he purchased the Lordship of Wymondham, a township on the verge of the Sherard estates. With the assistance of his steward, William Reeve, who was also his father-in-law and friend, Lord Harborough consolidated all the Sherard landholdings, including estates in Leicestershire, Rutland, and South Kesteven, before his death. As a member of the House of Lords for 29 years during the late Georgian period, there is no record of the Earl participating in debates and he was only in his place on 24 occasions. He did not attend debates on the American War of Independence, but he did attend the trial of Elizabeth Pierrepont, Duchess of Kingston in 1776 when she was found guilty of bigamy.
Personal life
Lord Harborough was married, and widowed, three times during his lifetime. On 17 May 1762, he was married to Catherine Hearst, eldest daughter and co-heiress of Edward Hearst, a Wiltshire landowner and one of the principal lay residents of the Cathedral close, Salisbury. As his wife predeceased her father, under the terms of her father's will, his fortune went wholly to his other daughter, Caroline, except for Aula le Stage, Hearst's house on the west side of the close, which went to Sherard. After her death in 1765, he remarried to Jane Reeve, the daughter of his friend William Reeve of Melton Mowbray, on 10 January 1767. Together, they were the parents of:
After her death in 1770, he remarried thirdly to Dorothy Roberts, daughter and heiress of William Roberts of Glaiston, on 25 May 1772. Through his marriage, he gained manorial rights at Thorpe by Water in Rutland. They were the parents of:
Lady Sophia-Dorothea Sherard, who died aged six.
In 1780, his elder sister, Lady Dorothy Tarkington, died and within twelve months, he lost his unmarried sister, Lady Lucy Sherard, his daughter Lady Dorothea Sophia Sherard, and his third wife, Lady Harborough, on 5 November 1781. Lord Harborough died on 21 April 1799 and was succeeded in the earldom by his son, Philip.