Mark Richard David Seaward (born 10 August 1938) is a British ecologist and lichenologist.
He was awarded the Acharius Medal in 2006 for lifetime contributions to lichenology.
He attended the University of Birmingham, graduating in 1959, and obtained an education diploma from the same institution a year later.
While teaching at the Loughborough Training College, he obtained an MSc from the University of Nottingham in 1965.
In 1989 he was appointed as chair of Professor of Environmental Biology.