Williamson was a direct descendant of the Nottinghamshire Royalist baronet, Sir Thomas Williamson (1609-57), whose son and namesake had acquired the Monkwearmouth estate on the north bank of the River Wear through marriage with the Northumberland heiress Dorothy Fenwick of Brinkburne. The estate, however, was on the geographically less favoured bank of the river, and, on taking control of the estate in 1819, Williamson’s finances became heavily encumbered. Returned as a Reformer for county Durham at the 1831 general election, he led the opposition to the Sunderland (South Side) docks bill and engineered its defeat in committee, only to see his own subsequent Sunderland (North Side) docks bill rejected in the Lords, where it had been entrusted to his father-in-law Lord Ravensworth.
At the 1832 general election Williamson was elected for the new county division of Durham North after a particularly acrimonious contest.
His one notable success while member for Durham North came in 1834 when he secured a charter for the North docks and subsequently commissioned Brunel to build the harbour. Before the work was completed, however, the cost had risen fourfold from its original estimate, and the docks failed to be profitable.
Financially drained by the North Dock scheme, Williamson economised by residing in Bruges, before returning in December 1847 to contest a by-election at Sunderland, which had been precipitated by Barclay’s resignation.
After a long illness, Williamson died at Whitburn in April 1861, survived by his wife and four sons.
