The president voted at about 8:05 a.m, the first person to do so in Polling Unit 003 at Sarkin Yara Ward in Daura Local Government Area.
It took Mr Buhari only a few minutes to cast his votes.
Mr Buhari arrived Katsina earlier on Friday alongside his wife, Aisha aboard a presidential jet.
He was subsequently flown to Daura by a presidential helicopter.