John McCallister (born 20 February 1972) is a former Northern Irish Unionist politician who was a Member of the Legislative Assembly (MLA) for South Down from 2007 to 2016.

He was initially an Ulster Unionist Party (UUP) representative, later serving as deputy leader, as well as an unsuccessful candidate in the 2012 leadership election.

On 14 February 2013, McCallister announced that he had resigned from the UUP due to its decision to engage in an electoral pact with the Democratic Unionist Party.

[8] After being called the "leader of the opposition" by culture minister Carál Ní Chuilín, McCallister said, "If I win the leadership I think that title could quickly catch on.

[10] On 14 February 2013, McCallister announced that he had resigned from the UUP in reaction to the decision to field a unionist unity candidate in the Mid-Ulster by-election.

[13] In July 2014 amid allegations of inappropriate behaviour by McCrea, McCallister resigned to resume sitting in the Northern Ireland Assembly as an independent.