The new county was named for Wills Hill, the Earl of Hillsborough, who served as British Secretary of State for the Colonies from 1768 to 1772.

[citation needed] On New Year's Day in 1914, the St. Petersburg-Tampa Airboat Line initiated the first scheduled commercial airline service in the world, from St. Petersburg to Tampa.

[citation needed] A narrow portion of Hillsborough County to the south, consisting almost exclusively of water, extends west to the Gulf of Mexico roughly along the Tampa Port Shipping Channel.

The northernmost tip of a spoil island just west of Port Manatee also lies in Hillsborough County.

[citation needed] Hillsborough is home to Alafia River State Park and Hillsborough River state parks, and to the C. W. Bill Young Regional Reservoir and Lithia Springs, one of the largest natural springs in Florida.

[citation needed] As of the 2020 United States census, there were 1,459,762 people, 539,919 households, and 338,683 families residing in the county.

U.S. Census Bureau 2010 Ethnic/Race Demographics:[21][22] In 2010, 6.0% of the Hillsborough's population considered themselves to be of only American ancestry (regardless of race or ethnicity.

About 27.12% of all households were made up of individuals, and 7.96% (2.35% male and 5.61% female) had someone living alone who was 65 years of age or older.

[30] According to the Secretary of State's office, Democrats are a plurality of registered voters in Hillsborough County.

Hillsborough County tends to lean Democratic, having not been won by a Republican presidential candidate from 2004 until 2024.

It is part of the politically important I-4 Corridor between Tampa Bay and Orlando, an area that historically decides most elections in Florida.

Hillsborough was considered a bellwether county, voting for the statewide winner in every presidential election from 1964–2012.

However, Republican senator Marco Rubio did win the county in his 2010, 2016 and 2022 senatorial campaigns and Republican Governor Ron Desantis won it in his 2022 gubernatorial campaign after the county supported Democrats for the previous three gubernatorial elections since 2010.

[32] Obama won Hillsborough again in 2012 over Republican presidential nominee Mitt Romney by roughly the same margin.

In 2016, Donald Trump became the first Republican since Calvin Coolidge in 1924 to win a presidential election without carrying the county.

The Board of County Commissioners, which composes the legislative branch, sets overall policy by means of ordinances, resolutions, and motions.

One amendment was approved in November 2002, adding the position of County Internal Performance Auditor to the government structure.

[34] Wise previously served as the county's deputy administrator and Tampa's chief financial officer.

[36] Hillsborough County's discretionary sales tax rate increased from 1% to 2.5% in January 2019.

The rate includes two surcharges approved by voter referendum in November 2018, 1% for transportation and 1/2% for schools.

The percentages of total employment by industry were: [38] In 2011, sales of all agricultural commodities produced in Hillsborough County were over $832,410,300.

Headquartered in the Ybor City District of Tampa, it is responsible for law enforcement services in the unincorporated areas of the county.

With these being the only jails in the county, other than juvenile detention facilities, the work release center, or holding cells located at multiple police stations and sheriff offices, all local agencies transport persons being arrested to one of the county jails.

The sheriff's office also provides security and protective services at the county courthouses in Tampa.

Fire service began in the 1950s as an all-volunteer force consisting of about a dozen loosely associated community-based organizations.

Since the 1997 consolidation of Hillsborough County Fire Rescue and Emergency Medical Services (EMS), the department has placed paramedics on each career, front-line apparatus.

These units operate out of 44 Fire Rescue stations located strategically throughout Hillsborough County.

Hillsborough County Fire Rescue and the Board of County Commissioners have implemented a plan to continue placing new fire rescue stations in areas where growth is occurring or gaps in coverage may exist.

[49] The Office of Emergency Management is a division of Hillsborough County Fire Rescue that is directly responsible for planning and coordinating the evacuation and sheltering of all county residents in the event of a natural or manmade disaster.

This interactive program was designed to assist the public in easily determining if they are in one of the five evacuation zones.