Sinceré Harris, a top aide to Mayor Cherelle L. Parker, is leaving the administration

Chief Deputy Mayor Sinceré Harris, who was campaign manager for Mayor Cherelle L. Parker and a top aide in her administration, is leaving city government, Parker announced Tuesday.

Harris is one of Parker’s “big three” of top aides, which also includes Chief of Staff Tiffany W. Thurman and Chief Deputy Mayor Vanessa Garrett-Harley.

Harris’ resignation, which takes effect later this month, was announced internally Tuesday in a meeting of top Parker administration officials, according to a person with knowledge of the decision who spoke on the condition of anonymity because they are not authorized to speak to the press.

Parker released a statement Tuesday after The Inquirer reported the move, saying she was “fully supportive” of Harris as she leaves “for a position in private practice.”

“I accept her departure with deep gratitude and understanding,” Parker said. “Harris has been at my side for over 3 and 1/2 years as I ran for Mayor and then during my first two years in office. She has done so with professionalism, drive, energy, and passion.”

The statement did not disclose what Harris’ next role will be or whether the administration planned to fill her city position.

Harris’ portfolio of duties and responsibilities, including labor relations, sustainability, and legislative and intergovernmental affairs, will be allocated to the executive team in the Parker administration.

Harris’ departure means Parker will soon be without both of her original chief deputy mayors, who were also seen as the architects of her victory in the 2023 mayoral election.

Former Chief Deputy Mayor Aren Platt resigned unexpectedly in 2024, less than a year into the mayor’s tenure. Platt, who has returned to Parker’s campaign as its executive director, was a member of the administration’s original “big three” before being replaced by Garrett-Harley.

Parker has long said she doesn’t want a single “big mahoff” to lead her administration and maintained the triumvirate structure for her top staff after Platt left. But over the last two years, Thurman has become an increasingly central figure in the administration, with Parker last year calling her the “chief air traffic controller.”

Throughout the drama surrounding Platt’s exit and Thurman’s growing role, Harris was seen as content with her lane, which includes serving as the administration’s top liaison to the state and federal governments.

A Philadelphia native, Harris graduated from Temple University and earned a master’s in business administration from Pennsylvania State University. Having worked primarily in state and federal politics, Harris was relatively new to Parker‘s orbit when she left a position in President Joe Biden’s administration to join the mayor’s campaign.

Under Biden, Harris served as an associate director for intergovernmental affairs focusing on climate and the environment and as White House liaison to the Environmental Protection Agency.

Prior to joining the federal government, she was executive director of the Pennsylvania Democratic Party and worked as a senior adviser for Biden’s 2020 campaign. She previously worked in legislative affairs for Democratic former Gov. Tom Wolf’s administration.

» READ MORE: Meet the staffers who ran Cherelle Parker’s historic campaign and will lead her mayoral administration

In 2023, Parker bested a crowded field of rivals in the Democratic primary before cruising to victory in the general election to become the city’s first Black female mayor. Her opponents included five of Parker’s former City Council colleagues.

Harris oversaw Parker’s $3.2 million campaign budget and staff.

Parker said she would “always be grateful” for Harris.

“I wouldn’t be here but for her work — as campaign manager and now as one of my two chief deputy mayors in my administration,” Parker said.

Once in the Parker administration, Harris managed intergovernmental and legislative affairs, sustainability issues, and the Department of Labor — including leading the administration’s negotiations with unions for city workers.

In that capacity, Harris was at the helm last July when District Council 33 of the American Federation of State, County and Municipal Employees, the largest municipal union for city workers, went on strike for just over eight days. The ordeal was a defining moment in the administration, with residents grumbling as “Parker piles” of uncollected trash mounted across the city while the union fought for higher wage increases.

» READ MORE: ‘They are my people’: Mayor Cherelle Parker on why she stood firm in the DC 33 city worker strike

In the end, DC 33 accepted a deal largely in line with Parker’s last offer before the strike began. That outcome allowed the administration to claim it had achieved Parker’s goal of reaching a “fair and fiscally responsible contract” but strained the mayor’s relationship with some allies in organized labor.

At a news conference announcing the conclusion of the strike, Parker strode into the Mayor’s Reception Room in City Hall alongside Thurman, Garrett-Harley, and Harris — all Black women at the height of city government — creating a memorable image of Parker’s leadership team.

“Harris was a key part of a historic era in the Parker administration, where three Black women ... worked side-by-side with Mayor Parker, the first woman to lead Philadelphia as Mayor, to govern the sixth largest City in the country,” the mayor’s office said Tuesday.

Staff writer Anna Orso contributed to this article.