The official Qatari News Agency said in an urgent dispatch, "His highness the father Sheikh Khalifa arrived in Doha."
It said the emir, crown prince Sheik Tamim and several members of the royal family welcomed the old emir at Doha airport.
Hamad toppled his father on July 27, 1995, days after the latter left Doha on a trip abroad, and arrested 36 of his followers.
Since then Khalifa has been living in exile in France.
2014: The Year in Music [PHOTOS]