Mubarak spent three decades in office before a popular uprising swept Egypt.
He was found guilty of complicity in the killing of protesters during the revolution. That conviction was overturned and was freed in March 2017.
His death was confirmed by Egyptian state news on Tuesday. Earlier in the day, the Al-Watan website reported that he died at a military hospital.
Mubarak underwent surgery in late January. His son Alaa said on Saturday that Mubarak remained in intensive care.
Born in 1928, Mubarak entered the air force as a teenager and went on to play a key role in the 1973 Arab-Israel war.
He became president less than a decade later, following the assassination of President Anwar Sadat.
He played a key role in the Israel-Palestinian peace process.
But despite the billions of dollars in military aid Egypt received during his time in power, unemployment, poverty and corruption continued to grow.
Discontent boiled over in January 2011, after similar protests in Tunisia led to the overthrow of the president there. Mubarak was forced to step down 18 days later.
