All operators with services in West Yorkshire are supporting the day, including Arriva, First and Transdev.
No special ticket will be required – passengers can hop on the bus most convenient for them and make as many trips as they like for free on any journey within West Yorkshire.
Mayor of West Yorkshire Tracy Brabin said: “With so many events taking place across the region I wanted to make it as easy as possible for people to attend, which is why I worked with local bus operators to fund our Free Bus Sunday for the Queen’s Platinum Jubilee celebrations.
“If you’re attending events in Saltaire, Ripponden, Longwood, Morley or Wrenthorpe, going shopping in one of our town and city centres or just visiting family and friends, there will be buses to take you there and back for free.
“I hope that our Free Bus Sunday will encourage as many people as possible to use the buses.
“Buses are still the best way to get around West Yorkshire and see the sights or get to work.”
Earlier this month, Ms Brabin announced fresh plans to reduce bus fares from September down to just £2 a journey.
The proposals will also see the multi-operator WY DaySaver tickets available through the MCard app and smartcard reduced from £5.50 to £4.50.
Journeys outside West Yorkshire on jubilee day will be charged at the normal fare for that part of the trip.