At 15, he was placed as a pupil with David Stephenson, the leading architect-builder in Newcastle and the designer of All Saints' Church and the original Theatre Royal on Mosley Street.

[4]: 31  His Friends strongly encouraged him to stay and work in London, but he was back in Newcastle by 1811 assisting Sir Charles Monck design Belsay Hall.

The first building Dobson designed is unclear, but his daughter maintained it was North Seaton Hall, near Ashington, built in 1813 and demolished in 1960.

His country houses are not well-known, as they generally are privately held, not large enough to be open to the public, and landscaped behind parkland and trees.

Architectural features of Dobson country houses include the use of golden sandstone, Corinthian or Ionic pillared entrance porticos, elegant staircases with beautiful ironwork balustrades leading to an upper gallery with matching iron balustrades, and an entry hall with a domed ceiling and glass centrepiece.

The quality of the stonework in all Dobson homes is superb, and it is believed that he regularly used the same team of stonemasons as he did with other craftsmen he employed.

[6] In 1824, several years before Richard Grainger did the same, Dobson presented plans to the council to purchase and develop Anderson Place in Newcastle's centre.

Dobson proposed a Mansion House as a "civic palace" with grand squares linked by wide tree-lined streets.

[6] In 1820, the Newcastle City Council authorized the demolition of the Chapel of St Thomas the Martyr at the north end of the Tyne Bridge so the road could be widened.

His original plan of 1848 showed an ornate façade with a vast portico having double colonnades and an Italianate tower at the east end.

[4] John Dobson argued for the role of the architect in building railway stations, and his Newcastle Central is regarded by many as the finest in England.

According to Gordon Biddle and Oswald Nock in The Railway Heritage of Britain: "Undoubtedly it would have been one of the finest 19th-century classical buildings in Europe had it been completed...

The train shed at Newcastle, the authors state, "was the first of the great arched roofs and represented a bold step forward which was copied by others".

Modelled after an elegant London shopping arcade, it had two office blocks facing Pilgrim Street and Manor Chare.

The arcade's front façade had six fluted Corinthian columns, and its interior was 250 feet (76 m) long with an arched Grecian-style ceiling with several domed skylights.

Giant Doric pilasters at the end of each terrace were faced with finely cut ashlar, more elegant and clean than the stucco used extensively in London at the time.

Grainger attempted to reduce the indebtedness by charging Dobson £250 for a staircase and painted ceiling removed from Anderson Place.

Dobson thought the amount was outrageous and an underhanded trick, expressing his indignation to Grainger in various surviving letters.

His youngest son, Alexander, Ralph, Dobson born November 1834, inherited his father's artistic genius, gaining first prize in architecture at University College.