Liggett ran for mayor of Cambridge in the 2022 mayoral election against incumbent mayor Kathryn McGarry. While on council, Liggett often found her self in opposition to McGarry on a number of controversial issues. In addition to her opposition of building an Amazon warehouse in Blair, Liggett also opposed the establishment of a consumption and treatment services site in the city, which McGarry supported.[10] Her reasons for running for mayor included concerns that residents were being ignored, mental health, addiction and homelessness issues and "respect for taxpayers' money".[11] In the election, Liggett defeated McGarry by just 1,126 votes. During the campaign, Liggett was hit by a car, breaking her foot in the process.[12] In her first address to council as mayor, Liggett stated the city was in a "state of social recession", and needs to be "uplifted with an emphasis on city-building, saying the city must 'aim higher'." She indicated that the city needs "accessible rehabilitation for people who use drugs", "mental health facilities", and "mandatory court-ordered drug treatment".[13]
As mayor, Liggett indicated she "does not expect" to use her new "strong mayor" powers, following the passing of the Strong Mayors, Building Homes Act by the provincial government.[14] She has also had to face local concerns over a homeless encampment in the city.[15] She has opposed the extension of Ion rapid transit, the region's light rail transit system to the city, favouring instead bus rapid transit, fearing light rail would bring problems to the downtown core, and the fact it would take a traffic lane away from Hespeler Road.[16] During her term in office, the city celebrated its 50th anniversary since its amalgamation in 1973.[17]
Mayor Liggett presided over a heated meeting discussing gender neutral bathrooms in a new city facility. A public speaker said, "You offer the universal open area for males, females and children to change and shower together. Part of the process of grooming children is establishing a connection, isolating a child, testing boundaries — of all which councillors, you're providing opportunities". Liggett responded "that has nothing to do with this facility".[18][19]