Over the course of his career, Clark delivered several named lectures and received multiple awards. In 1969, he was elected a fellow of the Royal Society of Chemistry. In 1989, he was granted honorary fellowship by the Royal Society of New Zealand. He became a fellow of the Royal Society of London and member of the Academia Europaea in 1990. Two years later, he was elected a fellow of University College London and the Royal Society of Arts, and in 2001 he was conferred with an honorary DSc by the University of Canterbury. Clark was appointed a Companion of the New Zealand Order of Merit in the 2004 Queen's Birthday Honours, for services to science and New Zealand interests in the United Kingdom, followed by elections as a foreign fellow of the National Academy of Sciences, India in 2007 and as an international member of the American Philosophical Society in 2010. In 2009, Royal Society of Chemistry awarded Clark the Sir George Stokes Award for his contribution to the application of analytical science to the arts and archaeology through his development of Raman microscopy for the identification of pigments.