U.S. Route 90 (US 90) in the state of Florida is the northernmost east–west United States Numbered Highway in the state and runs parallel with Interstate 10. US 90 not only passes through the county seats of 15 of the 16 counties it runs through on its course in Florida (the exception is Nassau County) and is also the road upon which many of the county courthouses are located, but it was the first paved road in Florida (from Jacksonville westward a few miles). It is never more than from Interstate 10 (I-10) throughout the state, except to the east of Jacksonville. It runs as a two-lane highway through most of the sparsely populated inland areas of the Florida Panhandle, widening to four lanes through and near several towns. The speed limit is for all rural points west of Monticello, and it is on all rural points from where it enters Madison County as far as Glen St. Mary.

Like all highways in Florida, US 90 always carries a state road number, which may or may not always be signed. These numbers are assigned by the Florida Department of Transportation (FDOT): State Road 10 (SR 10) from the Alabama state line to US 90 Alt./SR 10 east in Jacksonville with one exception: SR 10A between the western and eastern termini of US 90 Alt. in Escambia County, which carries SR 10. SR 212 from the US 90 Alt./SR 10 interchange in Jacksonville to the eastern terminus at SR A1A in Jacksonville Beach.

Concurrencies include US 98 in Pensacola, US 331 in DeFuniak Springs, US 221 in Greenville, US 301 in Baldwin, and US 1 in Jacksonville. Lesser concurrencies with state and county roads also exist in various parts of the state. The segment between US 319 in Tallahassee and US 441 in Lake City also includes part of the DeSoto Trail.

Route description

Escambia County, including Pensacola As it enters the Sunshine State from Alabama after crossing a bridge over the Perdido River, US 90 and the eastbound beginning of unsigned SR 10 passes by two roads for a local fish camp on the northeast side of the bridge then bends northeast toward the rural community of Beulah. This segment of the road is known as Mobile Highway. Halfway along this alignment a single truck weigh station that's accessible from both directions can be found on the south side of the road. Once it begins to turn more to the east again, US 90 becomes a divided highway before it shifts south towards Pensacola while US 90 Alternate (US 90 Alt.) stays to the north of the city taking SR 10. This stretch of highway is also known as Nine Mile Road. US 90 itself moves onto hidden SR 10A where it narrows back down to two lanes and then takes a turn to the southeast, still keeping Mobile Highway as the street name. From there, the road becomes the southern terminus of County Road 99 (CR 99), the westernmost two-digit route in Florida.

After passing by the Florida Division of Forestry's Beulah Fire Lookout Tower, and then a few schools and churches, the road crosses waterways such as Elevenmile Creek and then Eightmile Creek before entering Bellview. Here, the first major intersection is CR 173, better known as Blue Angel Parkway, and a county extension of SR 173. Next, it turns into a four-lane divided highway north of Godwin Lane, and then becomes the southern terminus of SR 297. The only other intersection south of this point is Bellview Avenue between there and a much more important intersection with the western terminus of SR 296 and eastern terminus of CR 296. From there, open space exists on the southwest side of the street which is interrupted only by one street, specifically CR 341 (Marlane Drive). The road then crosses a body of water known as Bayou Marcus Creek which leads to Crescent Lake, the southwest corner of which is flanked by the Osceola Municipal Golf Course. The road runs along the border of West Pensacola and Myrtle Grove until it reaches the intersection with SR 727 (Fairfield Drive) and is entirely within West Pensacola. Eastbound SR 727 provides the only northbound access to the next state route, because that route happens to contain a partial cloverleaf interchange with SR 295, which includes only east-to-south and west-to-north access from US 90, and south-to-east and north-to-west access from SR 295. Later it serves as the northern terminus of SR 295 Spur and eastern terminus of SR 298 (New Warrington Road). The road then approaches a bridge over some railroad tracks and then begins to turn more towards the east and less towards the south.

US 90 finally enters the city of Pensacola after the intersection of CR 453 (W Street) where it merges onto West Cervantes Street, which is also the name of a local street west of CR 453. Eight blocks later, US 90 encounters the intersection of US 98 and SR 292, and US 98 moves from a concurrency with SR 292 to one with US 90. Together US 90 & 98 run through the heart of Pensacola. Among the intersections they share are with US 29 where West Cervantes Street becomes East Cervantes Street. But US 29 has been overshadowed by a partial interchange with I-110 at exit 2. Two to three blocks later it encounters southbound SR 291 along Dr. Martin Luther King Jr. Drive (formerly Alcaniz Street), and northbound SR 291 along Davis Highway). Four blocks later, the US 90/98 concurrency ends at the intersection with SR 289, where US 98 turns south towards the Pensacola Bay Bridge and runs along the coast of the Gulf of Mexico toward Perry, Lakeland, and Palm Beach, while US 90 continues along Cervantes Street. Veering slightly to the right after the intersection with 15th Street, it crosses a bridge over Bayou Texar, and hits land again at the intersection of Bayou Boulevard across from the Bayou Texar Boat Ramp, which can only be accessed from Stanley Avenue a block east.

Pensacola Scenic Bluffs Highway After the eastern terminus of SR 296 at Perry Avenue, the name of the road changes to "Scenic Highway," becoming an official Florida Scenic Highway known as the Pensacola Scenic Bluffs Highway. It narrows down from four lanes to two lanes between Chipley Avenue and Strong Street, and it turns north where it runs along the west side of Escambia Bay. Along the way, it frequently encounters the CSX P&A Subdivision, a former Louisville and Nashville Railroad line that carried Amtrak's Sunset Limited from 1993 until 2005 when Hurricane Katrina truncated the line to New Orleans. The road moves closer to the tracks near Magnolia Point just south of Hyde Park Road. Most of the area along this segment is residential, and those that aren't normally tend to consist of either parkland or merely open space.

Despite having neither a state or county road designation, the intersection of Summit Boulevard is of importance because it leads to Pensacola International Airport. After another random series of local streets, residences and parks, US 90 approaches a signaled intersection with Langley Avenue, which is across the street from a wayside for Chimney Park along Red Bluff, the site of the former Hyer-Knowles Planing Mill, which was destroyed by Confederate General Braxton Bragg as part of an attempt to prevent the factory from falling into Union hands. This site has been part of the National Register of Historic Places since May 2012. Just west of a peninsula called Gulf Point, the last state highway US 90 encounters in the city is SR 742. From there it enters Ferry Pass, where it will remain through the rest of the county. US 90 then encounters the first of five interchanges with I-10 at exit 17 (which is a folded diamond interchange), just before I-10 crosses the Escambia Bay Bridge. Later, the P&A Subdivision branches off to the east at Lora Point in order to cross its own bridge across the bay while US 90 moves to the northwest along the coast of Macky Bay. The first intersection along this segment also happens to be the first major intersection, SR 290 (Olive Road). All other streets along this segment are local ones, and all on the west side of the road. However, when the coastline moves to the north it provides local streets on the east side. Once this happens, the route finally encounters the eastern terminus of US 90 Alt. where the scenic route officially ends, and it becomes a four-lane divided highway again before crossing some bridges along the swamps on the left side of the bay the first of which is for the Escambia River where it crosses the Escambia–Santa Rosa county line.

Santa Rosa County Not yet outside of the Pensacola metropolitan area, US 90 enters Pace and gains the name Caroline Street. After the intersection of CR 197A, the road turns northeast, where it crosses CR 197 (Chumukula Highway), and at County Road 197B (West Spencer Field Road) it turns east again. The road remains straight east and west as it encounters another segment of CR 197A. After the northern terminus with SR 281 the road curves northeast, and officially enters Milton. It then crosses a pair of bridges over Pond Creek, where it passes by Mayo Park.Mayo Park (Santa Rosa County Official Site) Just east of the intersection with Glover Lane, Old US 90, a former segment of US 90 veers off to the right, but it is only a local street. The rest of the area is surrounded by portions of city territory, which becomes more widespread as it approaches the southern terminus of SR 89 (Dogwood Drive), but also has a hidden concurrency with SR 89 east of there. A far more visible concurrency exists later on when the road curves back to the east where it meets the intersection with SR 87, the eastern corners of which also includes the intersection of the Blackwater Heritage State Trail.Welcome to Blackwater Heritage State Trail (Florida State Parks; including map) From this point on the road narrows down to two lanes as it runs through the Milton Historic District, an area that has been on the National Register of Historic Places since November 12, 1987 and also includes an intersection with CR 191, which contains the east end of Old US 90. The district ends as the road crosses a bridge over the Blackwater River, and leaves the city limits.