The Vanguard Progressive Unionist Party, also known as the Vanguard Ulster Progressive Party (and several variations of word order), was a political party which existed in Northern Ireland between 1973 and 1978.

It has its roots in the Vanguard wing of the Ulster Unionist Party who were opposed to the moderate policies of the party's leader and last Prime Minister of Northern Ireland, Brian Faulkner. After the suspension of the Stormont Parliament, Faulkener moved towards a policy of power-sharing with Nationalist and non-sectarian politicians under the Sunningdale Agreement. In opposition to this many in the Ulster Unionists broke away and founded a separate Vanguard Party under the leadership of the form Stormont Minister Willie Craig. The party joined in the contested a succession of elections to the brief Sunningdale Assembley, the February 1974 General Election, the October 1974 General Election and the 1975 elections to the Constitutional Convention. The latter three were fought as part of the United Ulster Unionist Council with the Democratic Unionist Party and the Ulster Unionists, where the anti-Sunningdale wing of the party was now in control.

Despite the "Progressive" part of its title, Vanguard is usually considered to have been a right-wing party. However there were occasions when it did not follow the same course as other right-wing or unionist parties. For example in the 1975 referendum on the United Kingdom's membership of the-then European Economic Community, it campaigned for the United Kingdom to remain a member whilst the other Unionist parties campaigned for withdrawal.

The Constitutional Convention was intended to serve as a forum to allow the politicians of Northern Ireland to draw up their own proposals for the political future of the province, though this proved unsuccessful. However it led to Willie Craig proposing a voluntary coalition with the Nationalist SDLP, something that many in Vanguard found repugnant. As a result the party was bitterly split, with many breaking away to form the United Ulster Unionist Party. Craig subsequently merged the remainder of Vanguard back into the Ulster Unionist Party. The Democratic Unionist Party has since become the main hardline Unionist party that offers an alternative position to the Ulster Unionists.

In the 1982 elections for the new Northern Ireland Assembly, Craig, who had once more left the Ulster Unionists after losing his seat at Westminster, revived the name Vanguard for his candidacy in East Belfast. However he failed to get elected.

Several prominent current Ulster Unionist politicians were member of Vanguard, including David Trimble (who briefly served as Deputy Leader), David Burnside (who was Vanguard's press officer) and Reg Empey.