Diana Caroline Whalen is a Canadian politician, who represented the electoral district of Halifax Clayton Park in the Nova Scotia House of Assembly from 2003-2013, and Clayton Park West from 2013-2017, as a member of the Nova Scotia Liberal Party.

The 2003 Nova Scotia general election was held on August 5, 2003, to elect members of the 59th House of Assembly of the Province of Nova Scotia, Canada. The ruling Progressive Conservative Party, led by Premier John Hamm, was reduced to a minority government.