The band was founded in 1969 by Jean Chocun, Jean-Paul Corbineau and Jean-Louis Jossic – all of whom remained members – hence the suggested name of Tri Yann an Naoned (Breton for "Three Johns of Nantes"), Jean and Yann being respectively the French and Breton versions of the name John.

They presented their final concerts in September 2021, a celebration of their 50th anniversary as a group, which was delayed by the worldwide corona virus pandemic.

In December 2022, co-founder Jean-Paul Corbineau died following a long struggle with leukemia.

Among their best-known songs are La Jument de Michao (including the chorus "J'entends le loup, le renard et la belette" i.e. "I hear the wolf, the fox and the weasel") and Dans les prisons de Nantes ("In the prisons of Nantes").

Tri Yann sang the role of Uther Pendragon in Alan Simon's rock opera Excalibur, as well as Louis XII of France in Simon's rock opera Anne de Bretagne.