Born in London in 1939, he studied at the Slade School of Fine Art. He moved to Donegal in 1973, and has since lived there and in Germany, Belgium and Italy. He was guest professor for painting at the Hochschule für Bildende Künste, Braunschweig, in 1995-96, and was elected to the Royal Hibernian Academy in 2001. He curated the "Pursuit of Painting" exhibition at the Irish Museum of Modern Art in 1997. His paintings demonstrate a classical approach to still lifes, landscapes and interior settings, which hint at larger narrative themes. A survey of his work from the nineties took place at the Hans und Sophie Tauber Arp Foundation, Bonn, Germany in 2000.

He exhibits work regularly at the Kerlin Gallery in Dublin. Other solo exhibitions include Museum of Modern Art Oxford (1983), Stedelijk van Abbemuseum, Eindhoven (1984), Städtische Kunsthalle Düsseldorf (1986), Ca di Fra, Milan (1999), Reeds Wharf Gallery, London (1996, 95), Edward Totah Gallery, London (1986, 85), Galleria Seno, Milan (1986), Sander Gallery, New York (1985), Barry Barker, London (1979), Mestna Galerija, Ljubljiana (1997), Orchard Gallery, Derry (1996, 88, 81).

His paintings have appeared in numerous group exhibitions in Ireland, Europe and the USA.

In 2005 a major exhibition of McKenna’s work dating from 1969 – 2004 was held as part of the Nissan Art Project.

An exhibition of Stephen McKenna's latest work can be seen at the Kerlin Gallery