Donna H. Cansfield is politician in Ontario, Canada. She is currently a member of the Legislative Assembly of Ontario, representing the Toronto riding of Etobicoke Centre for the Ontario Liberal Party.

Before entering provincial politics, she was a school trustee, and served as chair of both the Etobicoke Board of Education and the Toronto District School Board. She has also served as the Vice-Chair of the Toronto Foundation for Student Success, and as a Director of Beatrice House, a homeless shelter. Cansfield was first elected to the Etobicoke board in 1988, and became a co-chair of the TDSB in 2000. In the 2000 trustee's election, she successfully fought off a challenge Ihsam El-Sayed , who was part of a group which opposed Cansfield's endorsement of the school board's gay-inclusive policies.

Cansfield's political identity has been the source of some controversy in recent years. Until recently, she was a member of the now-defunct Progressive Conservative Party of Canada. Notwithstanding her commitment to social liberalism, she was generally regarded as being on the conservative wing of the Etobicoke Board of Education, and was also regarded by some as ambivalent in her opinion of Paul Christie (who was appointed by the provincial government of Mike Harris to oversee and reduce expenditures in the Toronto District School Board, and whose tenure in office was reviled by most left-leaning trustees).

Notwithstanding this, her involvement in the education community led her to oppose the policies of the Mike Harris and Ernie Eves governments, and to run for the Ontario Liberal Party in the provincial election of 2003. She was initially seen as a long-shot candidate against high-profile Progressive Conservative cabinet minister Chris Stockwell. Following Stockwell's retirement amid scandal in mid-2003, however, she emerged as the frontrunner and eventually defeated replacement PC candidate Rose Andrachuk by about 4500 votes. She was appointed Parliamentary Secretary to Ontario Minister of Energy Dwight Duncan on October 23, 2003.