William Steel Dickson (1744–1824) was an Irish Presbyterian minister and member of the Society of the United Irishmen, committed to the cause of Catholic Emancipation, democratic reform, and national independence.

His political career began in 1776, when he spoke and preached against the “unnatural, impolitic and unprincipled” war with the American colonies, denouncing it as a “mad crusade”.

On two government fast-days his sermons—on “the advantages of national repentance” (13 December 1776), and on “the ruinous effects of civil war” (27 February 1778) created considerable excitement when published.

In a sermon to the Echlinville volunteers (28 March 1779) Dickson advocated the enrolment of Catholics, and though induced to modify his language in printing the discourse, he offended “all the Protestant and Presbyterian bigots in the country”.

According to Dickson himself, he attended no further meetings of the Society, but devoted himself to spreading its principles among the volunteer associations, in opposition to the 'demi-patriotic' views of the Whig Club.

At a great volunteer meeting in Belfast on 14 July 1792 he opposed a resolution for the gradual removal of Catholic disabilities, and assisted in obtaining a unanimous pledge in favour of total and immediate emancipation.

Their avowed object was to strengthen the throne and give vitality to the constitution by “a complete and radical reform.” Dickson was nominated on a committee of thirty to summon a national convention.

The Irish parliament went no further in the direction of emancipation than the Roman Catholic Relief Act 1793, which received the royal assent on 9 April, and remained unextended till 1829; while the passing of Lord Clare's Convention Act, still in force, made illegal all future assemblies of delegates “purporting to represent the people, or any description of the people.” In March and April 1798 Dickson was in Scotland arranging some family affairs.

During his absence a plans were made for an insurrection in Ulster,[5] and soon after his return Dickson agreed to take the place of Thomas Russell, who had been arrested, as adjutant-general of the United Irish forces for county Down.

Unlike the more high-profile prisoners like O'Connor and MacNeven who would not be released until June 1802, Tennant, Dickson, and Simms were permitted to return to Belfast in January 1802.