Duguid was first elected to the Ontario legislature in October 2003.  He was appointed Minister of Energy and Infrastructure in 2010. He previously served as Minister of Aboriginal Affairs, and Parliamentary Assistant to the Minister of Municipal Affairs and Housing.

In his capacity as Parliamentary Assistant, Duguid was active in the creation of the Greenbelt, the reform of the Tenant Protection Act and the devolution of the OMERS pension plan.  He was also instrumental in the City of Toronto Act, improvements to the Municipal Act and the restructuring of the Ontario Municipal Board and Planning Acts.

Duguid's political career began in November 1994 when he was elected as a municipal councillor in the former City of Scarborough.  After amalgamation, he was re-elected as a Toronto councillor.  As chair of the Community Services Committee, Duguid led initiatives to create new permanent shelter spaces for the homeless, to improve fire and emergency services and encouraged investment in affordable housing.  The following term, Duguid became chair of Toronto's Works Committee, where he championed the city's waste diversion and disposal efforts, including the implementation of the hugely successful Green Bin Program for organic waste.  As chair of the Toronto Task Force on Community Safety, he drafted a crime prevention strategy for Toronto, adopted in March 1999, and helped create CityWatch.  He also developed a coordinated approach to address youth crime, which was adopted by Council in May 2002.

Duguid remains active in the community by hosting and participating in a number of community events including the annual safety showcase, his annual community picnic, greenspace clean-ups and tree planting.  In addition to all this, he also lends his time to improve access to sports and outreach for youth.