Fort Pierce is a city in and the county seat of St. Lucie County, Florida, United States. The city is part of the Treasure Coast region of Atlantic Coast Florida. It is also known as the Sunrise City. Per the 2020 census, the population was 47,297.

The city was named after the Fort Pierce Army post which was built nearby in 1838 during the Second Seminole War, and lasted until 1842. The military post had been named for Benjamin Kendrick Pierce, a career United States Army officer and the brother of President Franklin Pierce.

The first permanent settlement of the current city was during the 1860s. In 1901, the city was officially incorporated as a municipality. It was the largest city on Florida's Atlantic Coast between Daytona Beach and West Palm Beach until 1970, when it was surpassed by Melbourne.

According to the U.S. Census Bureau, the city has a total area of 20.8 mi2 (53.8 km2), of which 14.7 square miles (38.2 km2) is land and 6.0 square miles (15.6 km2) of it (35.00%) is water.

According to the U.S. Army Corps of Engineers, The Fort Pierce Beach Shore Protection project includes 1.3 miles of shore line running from immediately south of the Fort Pierce Inlet southward to Surfside Park. The project is on a two-year renourishment cycle due to impacts to the beach from the federal navigation project at Fort Pierce Inlet. This two-year renourishment cycle is a much shorter renourishment interval than what is typical for other projects along the east coast of Florida.

The initial construction of the project occurred in 1971 and the ninth nourishment was completed in May 2013. Completion of plans and specifications, advertisement and award for the 10th renourishment contract were completed in FY 2014. The project was scheduled to start mid-February 2015. Sand for the project is dredged from an approved offshore borrow area known as the Capron Shoal and then pumped via a pipeline onto the 1.3 miles of beach south of the Fort Pierce Inlet. The sponsor, St. Lucie County, is preparing a General Reevaluation Report (GRR) for the project at their own expense that will evaluate extending Federal participation for an additional 50 years. Current Federal participation expires in 2020.

The U.S. Army Corps of Engineers estimates the total cost of the project to be $75.9 million, with an estimated U.S. Federal Government share of $46.4 million. No funding for the project was requested by the U.S. President from the U.S. Congress in Fiscal Year 2016.

The Experimental Oculina Research Reserve preserves the Oculina Banks, a reef of ivory bush coral (Oculina varicosa) off the coast of Fort Pierce, Florida. In 1984, a 92 square-nautical-mile (316 km2) portion of these reefs was designated the "Oculina Habitat Area of Particular Concern". In 1994, the area was closed to all manner of bottom fishing and was redesignated as a research reserve. In 2000, the marine protected area was expanded to 300 square nautical miles (1,030 km2) and prohibited all gears that caused mechanical disruption to the habitat. The city is also known for its large manatee population.

Due to the devastation caused at the Fort Pierce City Marina by hurricanes Frances and Jeanne in 2004, FEMA mandated a plan to ensure that the rebuilt facility would be protected from future such events before FEMA would release funding for the repairs. Starting in 2012, construction began to create 12 artificial barrier islands including oyster beds, lime rock artificial reefs, mangrove fringes and coastal dune. The "core" of the islands was constructed of TITANTubes, sometimes referred to as geotextile tubes or geotubes, manufactured by Flint Industries and covered by a coastal marine mattress and then armor stone. The project was completed in 2013 after six years of planning, permitting and construction and a cost of $18 million.

Fort Pierce is located in the broad transition zone between a humid subtropical climate (Cfa), which dominates Central Florida, and within the northern extent of the tropical climate typical of South Florida.

As of the 2020 United States census, there were 47,297 people, 16,687 households, and 10,005 families residing in the city.

As of the 2010 United States census, there were 41,590 people, 15,207 households, and 9,515 families residing in the city.

As of the census of 2010, the population density was 2,021.9 inhabitants per square mile (780.7/km2). There were 17,170 housing units at an average density of 1,164.7 per square mile (449.7/km2).

In 2010, there were 15,207 households, out of which 32.9% had children under the age of 18 living with them, 37.3% were married couples living together, 19.6% had a female householder with no husband present, and 37.9% were non-families. 32.5% of all households were made up of individuals, and 11.7% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.50.

In 2010, in the city, the population was spread out, with 25.9% under the age of 18, 7.0% from 20 to 24, 13.3% from 25 to 34, 13.0% from 45 to 54, 9.8% from 55 to 64 and 6.8% who were 65 years of age or older. The median age was 35.2 years. For every 100 females, there were 97.4 males. For every 100 females age 18 and over, there were 94.9 males.

In 2010, the median income for a household in the city was $30,869, and the median income for a family was $36,337. Males had a median income of $32,412 versus $26,349 for females. The per capita income for the city was $16,782. 30.2% of the population were below the poverty line.

According to the U.S. Army Corps of Engineers, an average of 350,000 tons of waterborne commerce moves through the Port of Fort Pierce annually. Major commodities which are dependent on the port include citrus exports, cement and aragonite imports. The last navigation improvements at Fort Pierce were authorized by the U.S. Congress in the Water Resources Development Act of 1988 dated November 17, 1988 and construction was completed in August 1996. The existing entrance channel is 400 feet wide and 30 feet deep, the interior channel is 250 feet wide and 28 feet deep, the existing turning basin is 1,100 feet square and 28 feet deep, and the north access channel is located immediately north of the main turning basin is 1,250 feet long, 250 feet wide and 28 feet deep.

In late 2014 dredging efforts were completed in the port. The dredging effort included both beach placement of beach quality sand on the beach immediately south of the Inlet as well as placement of non beach quality sand in the approved offshore disposal area.

The city of Fort Pierce has a council–manager government form of local government. The offices of commissioner and mayor are nonpartisan, and have a term of four years.

Fort Pierce is located on U.S. Route 1, near its intersection with Florida State Road 70. Interstate 95 and Florida's Turnpike are nearby, at the west edge of town. The Intracoastal Waterway passes through the city. The nearest airport with scheduled passenger service is in Melbourne; the closest major airport is in West Palm Beach. The city itself has a general aviation airport, Treasure Coast International Airport.

Fort Pierce is served by the St. Lucie Transportation Planning Organization (TPO). The TPO is a Metropolitan Planning Organization (MPO), a federally mandated and federally funded transportation policy-making organization responsible for transportation planning, programming, and financing of State and Federal transportation funds for the City of Fort Pierce. The TPO is governed by a TPO Board, which is composed of elected officials, representatives from the St. Lucie County School Board, and representatives from Community Transit, a division of The Council on Aging of St. Lucie, Inc. The original bus system started as a demand response service bus in the 1990s; it only served St. Lucie County. Soon it expanded to a fixed route system, going to predetermined locations along a route. On June 3, 2002, the Florida Department of Transportation (FDOT) approved funding, expanding the bus service to Martin County, and it became the Treasure Coast Connector.

From 1894 to 1968 the Florida East Coast Railway served the city as a passenger railroad. Until a strike beginning in 1963, several long distance passenger trains from Chicago, Cincinnati and New York City made stops there, en route to Miami. These long distances trains included the Illinois Central Railroad's City of Miami and the Louisville & Nashville Railroad's South Wind both heading from Chicago; and they included the Atlantic Coast Line Railroad's East Coast Champion, the Havana Special, and the winter-only Florida Special originating from New York. Into the latter 1950s, passengers could take the Dixie Flagler to Chicago via Atlanta from the station. The FEC continued a six day a week Jacksonville-Miami train from 1965 to 1968, per court order.

Amtrak and the Florida East Coast Railway had been planning to make stations along Florida's East Coast. The cities cited by Amtrak and the Florida Department of Transportation included: Stuart, Fort Pierce, Vero Beach, Melbourne, Titusville, Cocoa, Daytona Beach and St. Augustine, Florida.