Stacey Hassard was first elected to the Yukon Legislative Assembly in the general election for the 33rd Legislative Assembly on October 11, 2011. He was re-elected in the general elections for the 34th Legislative Assembly on November 7, 2016, and the 35th Legislative Assembly on April 12, 2021.
During the 34th Legislative Assembly, Stacey Hassard was the Chair of the Standing Committee on Public Accounts.
On November 17, 2016 the Yukon Party announced that Stacey Hassard would be interim leader of the party. He served as interim leader of the Yukon Party until Currie Dixon was selected as party leader on May 23, 2020.
On September 21, 2021, it was announced that Stacey Hassard would be the Yukon Party caucus critic for Highways and Public Works.
Stacey Hassard was appointed to Cabinet on January 16, 2015 and served as Minister of Economic Development, Minister responsible for the Yukon Housing Corporation and Minister responsible for the Yukon Liquor Corporation (including the Yukon Lottery Commission) during the 33rd Legislative Assembly.
Stacey Hassard was elected Deputy Chair of Committee of the Whole on December 1, 2011 and served in that capacity until his appointment to Cabinet. During the 33rd Legislative Assembly he was appointed to the Standing Committee on Appointments to Major Government Boards and Committees (which he chaired), the Standing Committee on Public Accounts (where he served as vice-chair), the Standing Committee on Statutory Instruments, the Select Committee on Whistle-blower Protection and the Select Committee Regarding the Risks and Benefits of Hydraulic Fracturing.