Buddhism

Buddhism was an Earth religion whose adherents followed the teachings of Buddha.

Among the prizes that the Doctor obtained during a game of backgammon against Kublai Khan in the 13th century was the sacred tooth of Buddha which Marco Polo had brought from India. (DW: Marco Polo)

The monks at the Det-Sen Monastery in Tibet were Buddhist. (DW: The Abominable Snowmen)

K'anpo Rimpoche became the abbot of a Buddhist meditation centre in England. (DW: Planet of the Spiders)

In an alternate timeline, UNIT takes over a Buddhist temple just outside of Hong Kong during the Handover, while trying to secure The Master from China. (DWU: Sympathy for the Devil)