Thomas Plunkett studied Fine Art and English Literature at the University of Chester and postgraduate studies at The UCL Institute of Education,University of London.

In December 2022 Thomas held a solo exhibition titled "His Major Works" at the Royal Watercolour Society's gallery at 3-5 Whitcomb Street, London WC1, next to the National Gallery.

Thomas's exhibitions include The Royal Watercolour Society at Bankside Gallery, the Art on Paper Fair at the Royal College of Art, The Watercolour and Drawing Fair, London, The Royal Institute of Painters in Water Colours and The Royal Society of British Artists.

Thomas's work was also shown at The Singer and Friedlander/Sunday Times Watercolour Competition Exhibition held at the Mall Galleries which also toured to The Sculpture Hall, Manchester Town Hall.

Recently his work has been exhibited at Chris Beetles Gallery, London, Shenzhen International Watercolour Biennale and previously at the Glasgow Arts Club with the Royal Scottish Watercolour Society (RSW), Fabriano Museum, Fabriano, Italy, the Wagner Art Gallery, Sydney, New South Wales and the Wollongong City Art Gallery, Australia.

Thomas undertakes many commissions, with clients including IMG Media, St Albans Cathedral, Knebworth House, Deloittes and the University of Chester. Thomas is listed in Who's Who in Art and Antiques.

Thomas' work can be found in the collections of the BBC at Broadcasting house and in many private collections in the UK and worldwide, including those of the Bishop of St. Albans and HM Queen Elizabeth II.

Thomas's work featured in an Exhibition at the Royal Albert Hall in April and May 2011. The exhibition "A Year in the Life of the Royal Albert Hall" The exhibition was a culmination of a year long partnership between the Royal Watercolour Society and the Royal Albert Hall.

Thomas is an Honorary Teaching Fellow of the University of Chester.

From 2009 to 2012 Thomas was Treasurer of the Royal Watercolour Society.

Thomas is Past President of the Royal Watercolour Society (2012-2017).