[4] He was also inspired by his maternal grandfather, Leonard Fuller, a World War II veteran and career Army officer who directed the Model Cities Program in McAlester, Oklahoma, after his retirement from the military.

[9] In 2004, Holt returned full-time to Oklahoma, where he served as the state's campaign coordinator to reelect Bush.

[9] In 2006 he was appointed chief of staff to Oklahoma City Mayor Mick Cornett, where he served until his election to the State Senate.

[4] He succeeded Glenn Coffee, the first Republican Senate president pro tempore in Oklahoma history.

[13] In 2015, Holt worked on election reform, authoring a law that created an online registration system.

[15] In a preliminary vote, Holt voted for a proposed bill to prohibit physicians participating in abortions from obtaining or renewing Oklahoma licenses to practice medicine and to impose a one- to three-year prison sentence for performing an abortion.

[20] Holt was elected mayor on February 13, 2018, defeating Taylor Neighbors and Randall Smith in a nonpartisan race.

[25] Holt's second year in office brought the development and passage of MAPS 4, a $1.1 billion initiative to address 16 priorities.

[29] In 2019, Holt was elected to the leadership of the United States Conference of Mayors and named vice-chair of the International Affairs Committee.

[30] In 2020, he was elected a trustee of the United States Conference of Mayors and to the board of the National League of Cities.

[33][34][35] In 2019, he joined leaders of five other cities in signing an agreement to form Oklahoma's first Regional Transit Authority (RTA), with plans to build a metropolitan rail system in the years ahead.

[52] In June 2021, a publicly released poll of Oklahoma City voters found that Holt was favored by Republicans 54%-19% and by Democrats 61%-12%.

The pollster wrote, "In today's political environment, it is very unusual to see a candidate who is able to draw such support from members of both parties.

Holt was reelected to a second term on February 8, 2022, receiving 59.8% of the vote in four-way, nonpartisan race, 40 points ahead of his nearest competitor.

[58] In November 2022, Holt supported a bond issue for public education, a nearly $1 billion proposal for school infrastructure.

[59] In May, it was announced Holt would serve as dean of the Oklahoma City University School of Law starting July 1, 2023, while also remaining mayor.

[67] Holt and other proponents of the proposal argued that the team's presence in Oklahoma City was worth $580 million per year to Oklahoma City's economy, while economists who specialize in the study of stadium subsidies strongly criticized the deal and were skeptical of its purported benefits.

[68] In a December 2023 referendum, 71% of Oklahoma City voters approved a six-year sales tax to fund the arena.

[74] Holt served as chief of staff to Oklahoma City Mayor Mick Cornett at the time.