Greyhound USA operates a bus from Flagstaff to Las Vegas 3 times a day. Tickets cost $30 - $80 and the journey takes 5 h 28 min. Alternatively, American Airlines flies from Flagstaff to Las Vegas every 4 hours.
From Flagstaff bus to Las Vegas, NV. 5 h 28 min $40. From Flagstaff Amtrak train to Kingman Amtrak, taxi to Kingman, then bus to Las Vegas, NV. 6 h 10 min $133. From Flagstaff drive to Las Vegas. 4 h 10 min $30. From Flagstaff taxi to Flagstaff airport, fly to Las Vegas airport, then bus to Las Vegas. 4 h 45 min $212. From NAU Dome bus to Phoenix airport, fly to Las Vegas airport, then bus to Las Vegas. 5 h 53 min $294.