She served at the Emmanuel-Howard Park congregation in Toronto before entering politics and, since January 2018, is the minister for the Trinity-St. Paul's Centre for Faith, Justice and the Arts.

After her father's death from emphysema and witnessing her stepfather's suicide, she dropped out of school at Grade 10 to live on the streets[3] for four years.

[1][3] In 1988, after some church-shopping with her then-husband Don Zielinski she joined a United Church of Canada congregation in Richmond Hill, Ontario.

She earned her masters of divinity in 1995 and served a rural charge in Brucefield, Ontario for two years before beginning her ministry at Emmanuel-Howard Park United.

[2][9] DiNovo began hosting a weekly radio show, The Radical Reverend, on Toronto's CIUT-FM in 2000 which ran until 2006, before resuming in 2017.

[21][22] DiNovo defeated Liberal Sylvia Watson in the 14 September 2006 by-election to replace Gerard Kennedy in the Legislative Assembly of Ontario.

[23] In October 2006, a Toronto Star column by Carol Goar said DiNovo had brought a new clarity and assertiveness to the NDP caucus' voice in the Ontario Legislative Assembly.

[24] Since entering the Assembly, DiNovo has approached a variety of poverty-related issues, including raising minimum wage and welfare rates in the province, creating more affordable housing and ending the government's tax clawback of the federal child benefit supplement.

[24] Earlier in the year DiNovo had shared her experiences of drugs and poverty as a 15-year-old, in a TV interview first shown on VisionTV on 9 March 2006.

The Parkdale–High Park campaign featured the same three major candidates as the 2006 by-election, with Watson and David Hutcheon representing the Liberals and the Progressive Conservatives respectively.

[30] During the 39th Parliament, DiNovo introduced many other bills covering such concerns as repealing dog-breed specific legislation,[31] inclusionary housing,[32] and safe bicycle passing guidelines.

[33] She also co-sponsored an all-party bill, that became law, calling for the commemoration of the Ukrainian genocide known as the Holodomor on the 15th of November each year in Ontario.

[35] Like other districts bordering on the rail link to Pearson Airport from Union Station, she successfully made the project's potential environmental impact on the community as the main issue in the campaign, by coming out against the Liberal's proposal to first use diesel trains and then eventually electrify the line at some future date.

DiNovo successfully proposed a bill to recognize Post-Traumatic Stress Disorder (PTSD) as a work place injury for first responders fast-tracking their Workplace Safety and Insurance Board benefits.

In a 2017 episode of the television series Political Blind Date, DiNovo and Marie-France Lalonde discussed their differing perspectives on the issue of criminal justice and corrections.

She became the minister of the Trinity-St. Paul's Centre for Faith, Justice and the Arts effective January 1, 2018 and continues to present the Radical Reverend program on CIUT radio.