The father of Richard Oastler, he was born at Kirby Wiske near Thirsk, where, to his father's displeasure, he joined the Methodists at 16. He was in effect adopted by his uncle John Oastler, one of two brothers instrumental in the building of the town's WM chapel in 1766. He became a local preacher. At Thirsk he was a grocer, but had become a cloth merchant by the time he moved to Leeds in the late 1780s and continued so until 1801, when he became the Steward of the Fixby Estate near Huddersfield. He was a friend of John Wesley, who stayed with him in both Thirsk and Leeds. Becoming a 'Tom Painer', he sided with Alexander Kilham, giving him substantial support and helping to acquire Ebenezer Chapel, Leeds, in which the first MNC Conference was held in 1797. Later, friends persuaded him to return to WM.