John Gregg (1957 – 1 February 2003) was a senior member of the UDA/UFF loyalist paramilitary organisation in Northern Ireland. In 1984, Gregg seriously wounded Sinn Féin president Gerry Adams in an assassination attempt.
John Gregg, a prominent figure within the UDA/UFF loyalist paramilitary group in Northern Ireland, attempted to assassinate Sinn Féin president Gerry Adams in 1984. This resulted in serious injuries for Adams.