In a statement, Baroness Eileen Paisley said her husband died on Friday morning.
"Although ours is the grand hope of reunion, naturally as a family, we are heartbroken," she said. We loved him and he adored us and our earthly lives are forever changed," she said.
Baroness Paisley said that his funeral would be private.
David Cameron said Mr. Paisley was one of the most forceful and instantly recognisable characters in British politics for nearly half a century.
He described him as a controversial politician but said his contribution in his later years to stability in Northern Ireland was "huge".
"In particular, his decision to take his party into government with Sinn Féin in 2007 required great courage and leadership, for which everyone in these islands should be grateful. I saw him most in the House of Commons where his great oratory stood out. He had a deserved reputation as one of the most hard working and effective MPs,” Cameron said.
First Minister and Democratic Unionist Party leader, Peter Robinson said that during the height of the Troubles, the "sure and certain ring" of Ian Paisley's voice had a "special resonance" with the people of Northern Ireland.
"I don't think that there's anyone who has had more influence in Northern Ireland over the years," Mr Robinson said.
"Even those who thought the least of his politics thought the most of him as a person."
He said those who knew Ian Paisley knew his priority was his faith - above all else in life.
"In terms of Ian Paisley's political contribution, I think there are many people who look at his early days in the context of the more stable and peaceful society that we have today.
"The Ian Paisley of those days was an Ian Paisley that was keeping together a unionist community that felt it was under fire, that it had no friends to help it constitutionally, that its representatives were being picked off, there was genocide along the border.
"In those circumstances, the sure and certain ring of Ian Paisley's voice and his message, I think, had a special resonance with the people of Northern Ireland and that can be seen by the rise in support that he got over the years."