There are, and very many. Direct flights between Bali airport in Denpasar and Changi in Singapore are operated by Air Asia (on Airbus A320), Singapore Airlines (Boeing 777-200), Valuair and Jetstar (on the same Airbus). You can get on the flights of European or Middle Eastern companies, for example, KLM or Qatar, which fly to Amsterdam or Doha and make a docking in Bali. The journey takes about 2 hours and 30 minutes. Flights are made every day, the cost of the flight is from 5 thousand rubles one way.