Through a long career at the Globe, he was a reporter, Toronto- and Ottawa-based national political columnist, member of the editorial board, deputy managing editor, and Africa-based correspondent during the last years of apartheid.
Since leaving the Globe he has been published by the newspaper on a freelance basis as well as by CBC News Online, the Toronto Star and the National Post.
On 13 December 1971, Valpy revealed in an article the secret deal brokered by Justice William Henderson to end the trial of the "Kingston 13".
He was the 2011–2012 Canwest Global Fellow in Media at University of Western Ontario and was awarded the 2012–2013 Atkinson Fellowship in Public Policy.
He continues to write as a freelance journalist with pieces published on the CBC News website and the Toronto Star as well as The Globe and Mail.
Valpy co-authored three books (two on Canada's Constitution and the third on the 21st-century generation of new Canadian adults), produced public affairs documentaries for CBC Radio, contributed chapters to several books on public policy issues and written for Maclean's, Time Canada, Policy Options, Shambhala Sun and Elm Street magazines.