Inglis went to North America and became a master in a church school in Lancaster, Pa., in 1757. In 1758, in England, he was ordained deacon and priest. Sent to Dover, Del., he undertook evangelical work among the Mohawk Indians. In the 1760s he served as assistant to the rector of Trinity Church in New York City. Because he supported the British during the American Revolution (1775–83), his church was burned and his property confiscated; in 1783 he went to Nova Scotia.

In 1787 Inglis was consecrated the first Anglican bishop of Nova Scotia and its dependencies—Newfoundland, Prince Edward Island, Quebec, and Bermuda. The church academy he founded at Windsor, Nova Scotia, in 1788–89 was granted a royal charter in 1802 and later became the University of King's College (located since 1923 in Halifax). In 1796 Inglis retired to a farm near Halifax to write, and in 1808 he was made a member of the council of Nova Scotia.