Cymdeithas o bobl sy'n gweithredu'n ddi-drais dros y Gymraeg a chymunedau Cymru fel rhan o'r chwyldro rhyngwladol dros hawliau a rhyddid. Mae Cymdeithas yr Iaith eisiau sicrhau cyfle cyfartal i’r Gymraeg, ac mae’n ymgyrchu trwy ddulliau di-drais dros hawliau i bobl Cymru ddefnyddio’r iaith ym mhob agwedd o'u bywydau.

Cymdeithas yr Iaith Gymraeg is a group of people who campaign for the Welsh language and the communities of Wales. They recognise that the campaign for Wales' unique language is part of a wider world-wide struggle for minority rights and freedoms. Cymdeithas yr Iaith is a group of people who campaign positively in a non-violent way for the rights of the people of Wales to use the language in every aspect of their life.