The Jacksonville Sheriff's Office (JSO) is a joint city-county law enforcement agency, which has primary responsibility for law enforcement, investigation, and corrections within the consolidated City of Jacksonville and Duval County, Florida, United States.

A town ordinance in 1845 required all free males living in Jacksonville to participate in evening patrol duty.

4 was passed by the Florida State Legislature allowing the governor to abolish all offices in Jacksonville and to make new appointments to fill the vacancies.

On June 2, 2022, Mike Williams announced his retirement a year prior to the end of his second term.

Public criticism that the leader of law enforcement was violating the rules forced Williams to make a choice.

Undersheriff Pat Ivey was appointed by Governor Ron DeSantis to replace Williams, and was sworn in on June 11, 2022.

[9] Prior to the Police/Sheriff merger in 1968, Jacksonville Police Headquarters, located at 711 Liberty Street was dedicated November 30, 1964.

[14] On February 18, 1974 ground was broken for the Police Administration Building at 501 East Bay Street.

[15] The PMB provided just 215 parking spaces for 739 employees, requiring lease of a grass lot across the street.

The fueling station was the only police function destined to remain at East Bay Street.

[16] The Florida Blue Building (FBB) is actually multiple structures located on eight acres on Riverside Avenue in the Brooklyn neighborhood.

In addition to room for growth, the location offered emergency backup power; maintenance provided by the building's owner would result in significant savings for the city.

[17] In early 2023, JSO and the city began discussions regarding a department move from the PMB to a Brooklyn location.

[17] The City Council approved a multi-year lease in September 2023 for space in the Florida Blue Building for their JSO Homeland Security Department and select crime labs.

[17] In January 2025 the Mayor’s Budget Review Committee agreed to send legislation to city council for an amended and restated lease that would include 341,959 sq ft (31,769.0 m2), nearly 60% of the tower.

[17] The JSO is headed by the sheriff, a Florida constitutional officer elected to a four-year term.

The largest is the John E. Goode Pretrial Detention Facility (PDF), constructed in 1990[14] and located in downtown Jacksonville.

Sixteen years of research, development and planning culminated in the opening of the John E. Goode Pretrial Detention Facility in 1991.

The city began about constructing a new jail elsewhere and possible uses for the Police Memorial Building when the department vacates it.

[24] The City Council allocated $9 million in 2024 for infrastructure improvements that should extend five years to the lifespan of Goode while planning continues for a new facility.

[25] Following the headquarters move to Florida Blue, the Police Memorial Building might be utilized as on-site infirmary for the Goode Pretrial Detention Center.