Ohio Department of Health director (2019–2020)
In February 2019, Ohio governor Mike DeWine made Acton his final cabinet pick as director of the Department of Health. Acton was the first woman in the post. The two previous incumbents were a lawyer and a marketing director; DeWine mentioned wanting to "rethink how we approach this department".
In 2020, before and during the COVID-19 pandemic, Acton advised DeWine, who became the first U.S. governor to close schools and limit gatherings to 100 people. Acton soon estimated that Ohio's then 5 confirmed cases likely translated to 100,000 actual cases, making national news. In mid-March, she predicted cases could peak in late April to mid-May.
On March 12, Acton said of the pandemic, "This will be the thing this generation remembers." Ohio House Minority Leader Emilia Sykes called her "the real MVP of Ohio's coronavirus response." The Dayton Daily News called her "Ohio's trusted face during the pandemic."
Acton was an advocate of postponing the 2020 Ohio Democratic presidential primary, which was slated for March 17, 2020. The day before the scheduled election, DeWine canceled it, but a judge ruled he did not have the authority to do so. Acton then ordered polling places closed due to a public health emergency. It was later determined that the election would be conducted entirely by mail-in absentee ballot for those who had not participated in early voting. In April 2020, CNN called her "the Buckeye state's version of the straight-talking Dr. Anthony Fauci".
On April 1, DeWine was reported as "quick to defer to Dr. Acton for specific questions on the virus and its spread" during daily news briefings, "reminding Ohioans that the state's decisions are driven by science."
In May 2020, a group of 35 gyms sued the Ohio Department of Health, Acton, and the Lake County General Health District over COVID-related health restrictions, and Lake County Court of Common Pleas Judge Eugene Lucci issued a preliminary injunction blocking the state from "imposing or enforcing penalties solely for non-compliance with the director's order" against gyms and fitness centers, "so long as they operate in compliance with all applicable safety regulations." The state appealed the decision, but Acton had signed an order permitting gyms to reopen in the interim, and a court of appeals later dismissed the case as moot.
Beginning in May 2020, protesters began showing up at Acton's home in Columbus and at press conferences. Acton was assigned a security detail.
On May 20, 2020, the Ohio Senate unanimously voted against a proposal advanced by state House Republicans (and approved by the House on a nearly party-line vote) that would have limited the power of DeWine and Acton by restricting Ohio Department of Health orders to 14 days and requiring any extensions to be approved by a state joint legislative committee. After Republican state legislators and then-Speaker of the House Larry Householder introduced bills that she believed would violate her Hippocratic Oath, Acton resigned on June 11, and became a chief health advisor for DeWine's administration. She has said that her resignation had nothing to do with protesters or the controversy over her and DeWine's stay-at-home orders. Lance Himes succeeded her as interim director. In August, she announced she had left her position as advisor to the administration.
Due to her work as the Director of the Ohio Department of Health, she received a Profile in Courage Award from Caroline Kennedy and Jack Schlossberg. The New York Times called her "The Leader We Wish We All Had".