Mr Collum, 58, who is currently SmithKline's finance director, will replace Lord Henry Chilver, who said earlier this year he would leave his post. His appointment takes effect from the 1 October.
Before joining SmithKline Beecham in 1987, Mr Collum was finance director of Cadbury Schweppes, the maker of Dr Pepper and Seven Up and now the world's third-largest soft-drinks maker.
Like most biotechnology companies, Chiroscience is still reporting losses while it develops what it hopes will be profitable drugs, and analysts said Mr Collum's nomination could help raise the company's profile.
It expects this year to start selling its first major drug, Chirocaine, an anaesthetic used in surgical epidurals.