Ryan worked in a variety of media, including oil paints, watercolours, charcoal, pencil and red and brown chalks.

Some of his portraiture subjects include Ronnie Delaney, Patrick Hillery, Seán Keating and Éamon de Valera.

[3] Ryan's medallic work included designing the old Irish one pound coin and the Millennium fifty pence piece.

During his ten-year presidency of the Royal Hibernian Academy, he undertook the task of successfully completing the unfinished RHA Gallagher Gallery in Dublin.

He died in Blanchardstown, County Dublin on 15 September 2021, a day before his 92nd birthday.