Denness played for England in 28 Tests and was captain on 19 occasions, winning six, losing five and drawing eight matches. He made his Test debut in the final test against New Zealand at The Oval in 1969. After the cancellation of the 1970 South Africa tour, Denness played in the first match against the Rest of the World XI in 1970, before being dropped. He was vice-captain on the tour to India in 1972-3, captained by Tony Lewis, and he was appointed to replace Ray Illingworth as captain in September 1973.