He was educated at Ysgol Maes Garmon in Mold, and Aberystwyth University"s Department of Theatre, Film and Television Studies.
Best known for playing Alfie Butts in the British Broadcasting Corporation sitcom My Family, Meilir has also appeared in a number of popular television shows such as Afterlife and Terry Pratchett"s Hogfather on Sky One. He has also featured in a number of films, including The Baker and the 2014 film Pride, directed by Matthew Warchus. In 2006, he appeared in the Doctor Who episode "The Runaway Bride".
He is well known on Welsh television for his roles in an extensive range of shows including Y Pris, Caerdydd, Teulu, Tipyn o Stad, and Cyw.
He plays the lead role of Trefor the taxi driver in Gwlad yr Astra Gwyn, for which he received a British Academy of Film and Television Arts Cymru nomination as best actor in 2013, and was the original Rapsgaliwn. Meilir has toured with numerous theatre companies including Theatr Genedlaethol Cymru, Theatr Fran Wen, and Bara Caws.