In 1785, Ibbetson began exhibiting at the Royal Academy with View of North Fleet. Mitchell calls George Biggin (1783), which is one of Ibbetson's earliest known works, "an accomplished full-length portrait in the Gainsborough tradition, [which] should be considered as a milestone in the development of an artist who was entirely self-taught". Through the efforts of Captain William Baillie in 1787, Ibbetson was made draughtsman to Colonel Charles Cathcart on the first British embassy to Peking (Beijing); he made many watercolor drawings of the animals and plants on the journey. While he was away, his Ascent of George Biggin, esq. from St. George's Fields, June 29th 1785 was exhibited at the Royal Academy to great critical and popular acclaim.
In 1789, Ibbetson went to visit the Viscount Mountstuart at Cardiff Castle in Wales. He spent decades drawing the scenery there and, according to Mitchell, "[h]is detailed watercolours of iron furnaces, coal staithes, and copper mines foreshadow the work of Joseph Wright of Derby and J. M. W. Turner and constitute an important record of the early industrial developments in that region, but are less well known than his more numerous scenes of folk life and picturesque scenery." After a visit to the Isle of Wight in 1790, he began painting shipwrecks and smugglers. David Murray, 2nd Earl of Mansfield, and his wife commissioned Ibbetson to decorate Kenwood House, in 1794. This distracted him from the death of his wife and caring for their three children. Her death had "provoked a minor nervous breakdown, exacerbated by near destitution", but the Kenwood project relieved that stress. Four years later, he moved to Liverpool to work for Thomas Vernon. In 1801 he married his second wife, Bella Thompson, and moved to Ambleside.
Ibbetson acquired several generous patrons in Liverpool and in Edinburgh: William Roscoe, Sir Henry Nelthorpe, and the Countess of Balcarress. The last prompted him to write and publish his instruction manual An Accidence, or Gamut, of Painting in Oil (1803). In 1803, he met the Yorkshire philanthropist William Danby and in 1805 moved to Masham to be near him. The next 14 years of his life were the most settled of his life.
Ibbetson died on 13 October 1817 and was buried in the churchyard of St Mary's, Masham.
Benjamin West described Ibbetson as the "Berchem of England" in recognition of his debt to the Dutch 17th century landscape painters. According to Mitchell, "[h]is watercolours are prized for their delicacy and sureness of line". Many were engraved for projects such as John Church's A Cabinet of Quadrupeds and John Boydell's Shakespeare Gallery.