Lined up in long rows of chairs, 10,264 monks in crimson and saffron robes listened to prayers, chanted and filed past officials and their family members to collect rice and cash donations.
Buddha's birthday is celebrated in other parts of Asia -- including India, Sri Lanka, Laos, Thailand and Cambodia.
Many poured water on a Maha-Bodhi tree at the pagoda and some released captive fish and birds to accrue good karma.
Junta’s take over
Since the coup that ousted civilian leader Aung San Suu Kyi, more than 1,800 people have died in a brutal military crackdown on dissent, according to a monitoring group.
Some monks have joined street protests opposing the power grab, while other religious leaders have defended the military junta.
Ahead of Buddha's birthday, a group of Mandalay monks opposed to the coup urged other holy men not to participate in the junta-organised event.
Junta hosted ceremony
The last time the event was held in 2019, prior to pandemic disruptions, an estimated 30,000 monks attended.
Government officials and representatives from a military-linked political party hosted the religious ceremony near a former royal palace on Saturday -- the day coinciding with a full moon.
Mandalay monk Ugga Nyana insisted participation in ceremony was not a political statement, and the clergymen came in the name of love.
A monastic code prohibits some 300,000 of the clergy in Myanmar from voting or taking part in political demonstrations.
But monks in the Buddhist-majority country are seen as having supreme moral authority, and at times have rallied opposition to military regimes that ruled Myanmar for 50 years before its decade of democracy.
Junta’s hardline control
Myanmar's military is accused of committing genocide against the mostly Muslim Rohingya minority in 2017. Since then, about 740,000 people have fled to neighbouring Bangladesh to escape the violence.
The 2021 coup exposed factions in the monkhood, with hardline nationalist senior clerics supporting the military, which they believe is staving off what they say is a slow Islamic takeover, despite Muslims making up less than five percent of the population.