He was the chief of Jamaat-e-Islami, Pakistan's leading religious group, for 22 years before stepping down in 2009.
In November, Ahmed escaped unhurt from an assassination attempt when a suicide bomber detonated explosives near him.
He was a strong critic of the U.S.-NATO participation in the civil war in neighboring Afghanistan.
Ahmed died Sunday morning in Islamabad. He had suffered from heart disease for years.
