Interstate 85 (I-85) is a part of the Interstate Highway System that runs from Montgomery, Alabama, to Petersburg, Virginia. In the U.S. state of North Carolina, I-85 crosses the entire state from southwest to northeast (though is signed north–south), at the South Carolina state line near Grover to the Virginia state line near Wise. Running for over , the segment of I-85 is the longest of the five states it passes through and the second-longest Interstate Highway in North Carolina after I-40.

From southwest to northeast, I-85 crosses the large Piedmont region through its course in the state. Within this region, the Interstate connects three of the state's four most populous cities, Charlotte, Greensboro, and Durham. I-85 also serves to connect several smaller communities and suburban cities, such as Gastonia, Salisbury, High Point, and Henderson. Landscapes along the route include rolling hills and gently sloping terrain of the Appalachian Mountains at its southernmost stretch, the urbanized neighborhoods of the Piedmont cities through the center of North Carolina, and flat farmlands in the northeast towards Virginia.

Along its route, the Interstate parallels several older U.S. Routes for its entire length. It follows US 29 from South Carolina to Greensboro, US 70 from Greensboro to Durham, US 15 from Durham to Oxford, and US 1 from Henderson to Virginia. It shares an extensive concurrency with I-40 from Greensboro to Hillsborough, and has four auxiliary routes: I-285, I-485, I-785, and I-885. The first segment of I-85 to be complete was an segment through Mecklenburg County, opened in 1958. Later segments were eventually completed through bonds, contracts, and extensions, with the final segment opening in 1972. Since then, most of the route has been widened and renovated to accommodate rapid growth within the region.

Route description I-85 is maintained by the North Carolina Department of Transportation (NCDOT) for its entire length in the state and designated as a Blue Star Memorial Highway. The Interstate carries an average annual daily traffic volume of approximately 65,000 vehicles a day; roughly 25–40% of that traffic is commercial vehicles. In 2023, the busiest stretch along the Interstate was from the Statesville Avenue interchange to Graham Street in Charlotte, which carried a total of 200,529 vehicles per day. The lowest number was 20,224 vehicles per day at the US 1 interchange near Henderson and Middleburg. I-85 for most of its length in the state is generally a four to eight-lane configuration, with the exception of Durham, where it widens to ten lanes briefly. All of I-85 is a part of the National Highway System, a network of roads important for the country's economy, defense, and mobility.

South Carolina to Charlotte

I-85 enters Cleveland County, North Carolina from Cherokee County, South Carolina, in the town limits of Grover. Most of the Interstate for its first few miles passes into gently rolling terrain and is primarily rural in nature. The interstate comes to the interchange with NC 216, which gives access to Kings Mountain National Military Park, with the welcome center shortly after. Later, the southbound lanes have an exit for US 29, which merges onto I-85 and begins a concurrency. At mile marker 10, the Interstate meets US 74 at a weave interchange and US 29 splits off from I-85 for US 74 east.

At this point, I-85 crosses into Gaston County. It enters suburban areas and traffic begins increasing from here. The Interstate reaches the city limits of Gastonia and has an exit for NC 274 (Bessemer City Road). Then it has a major interchange with US 321, signed north for Lincolnton and south for the city's main business district. Past it, I-85 turns southeast, then east as it goes through more suburban and residential areas of the city. Along here, it intersects more state highways serving as Gastonia's main thoroughfares, including NC 7 (Ozark Avenue), NC 279 (New Hope Road), and NC 7 (McAdenville Road/Main Street) again; NC 7 provides access to the town of McAdenville. Just east of McAdenville, I-85 crosses the South Fork Catawba River on the William James Pharr Bridge. From here, the Interstate passes through considerably high residential development as it continues on its eastward track to Belmont. The Interstate then has an exit for Belmont at Main Street and passes right off the campus of Belmont Abbey College as it reaches another interchange for Belmont with NC 273 (Beatty Drive) one mile later, then crosses the Catawba River on the Cameron Morrison Bridge, entering Mecklenburg County.

Charlotte to Greensboro The interstate enters into Mecklenburg County, where it comes to the nearby weigh station, which occasionally serves trucks in both directions. I-85 traverses near the station building for Fox affiliate WJZY. I-85 comes to I-485, the beltway around Charlotte, with the stack interchange. This stretch of I-85 is frequently congested, in result of the ramps from I-485 inbound merging into one on southbound I-85. The interstate subsequently comes to the exit for the Charlotte Douglas International Airport via Little Rock Road at a single-point urban interchange (SPUI) and enters into Charlotte. Inside the city, the interstate comes to the interchange with Billy Graham Parkway, alongside two more single-point urban interchanges with NC 27 (Freedom Drive) and NC 16 (Brookshire Boulevard).I-85 comes to the interchange with I-77 and US 21 with a hybrid interchange containing several flyover ramps. I-85 traverses the northern outskirts of Uptown, before coming to the exits with Graham Street, Sugar Creek Road, and North Tryon Street. It is in this vicinity, where I-85 continues northward and enters into the University City district. I-85 comes to the junction with NC 24 (Harris Boulevard) in this stretch, crosses Mallard Creek, and comes to the turbine interchange with I-485.

Northeast of Charlotte, I-85 continues in the northeast-southwest orientation when traveling into Greensboro. Upon crossing into Cabarrus County, the interstate enters into the western areas of Concord. The corridor comes to exit 49 (Bruton Smith Boulevard/Concord Mills Boulevard), which gives access for several major attractions such as the Concord Mills Mall and Charlotte Motor Speedway. Several miles later, it comes to the diverging diamond interchange with NC 73 and then crosses Coddle Creek. It comes to another junction with US 29, alongside US 601. While heading into Kannapolis, the exit of which US 29 gives access to the North Carolina Research Campus. US 601 merges onto I-85, forming another concurrency, in which the two routes continue northward and come to one surrounding rest area. The highway traverses in the southern outskirts of Kannapolis with several exits available, then the road crosses the Cold Water Creek, which parallels the highway, before entering Rowan County. I-85 enters into the combination of suburban and rural development, while going into the southern areas of Salisbury, in which US 601 diverges from I-85 when the interstate comes to the exit with Jake Alexander Boulevard. Continuing Salisbury, I-85 comes to the single-point urban interchange with US 52. In this vicnity, US 52 merges onto I-85, in which the two routes exits Salisbury. Inside Spencer, I-85/US 52 enters Davidson County and crosses the Yadkin River on the Yadkin River Veterans Memorial Bridge. The route then comes to the interchange with US 29, US 70, and NC 150 near the unincorporated community of Linwood. This interchange gives direct access to NC 150 northbound and US 29/US 70 southbound. US 29 and US 70 converge with I-85/US 52, before comes to the half-interchange, which is the southern terminus of I-285. This interchange is accessible to only northbound traffic, and gives access to Winston-Salem. It is this vicinity, all three U.S. Highways that overlapped I-85, merges onto I-285.

After the interchange, I-85 turns slightly east for and intersects NC 47 (Hargrave Road). Because the previous exit is northbound-only, drivers going southbound must use NC 47 to access I-285. After its interchange with NC 8 (Cotton Grove Road), which is the main exit for Lexington, I-85 enters a large forest and crosses Abbotts Creek, then has an interchange with US 64. Past Holly Grove Road, the northbound lanes cut under the southbound lanes and cross Hamby Creek, diverting traffic to the left side of the road. The reversed lanes of I-85 then pass over Squire Bowers Road and reach a rest area, as well as access to the North Carolina Vietnam Veterans Memorial Park. Once the reversed lanes of the Interstate cross Johnsontown Road, the northbound lanes pass above the southbound lanes and return to the normal direction (right side of the road).

The forest gradually thins out and gives way to the city of Thomasville, where I-85 meets NC 109. It crosses into Randolph County as it enters the city of Archdale and intersects NC 62. I-85 enters High Point and has a parclo interchange with I-74, which gives east access to Asheboro and west access to Winston-Salem. I-85 then traverses into another forest with further trees lining the median, while crossing into the Randolph and Guilford branches of the Richland Creek, before the interstate enters into Guilford County. Going towards Greensboro, I-85 have the southbound interchange with US 29 again. US 29 forms a brief concurrency with I-85 before the route enters suburban areas once more and reaches a very large and complex interchange with Groometown Road, Grandover Parkway, I-73, US 220, and US 421. It is also at this junction, where US 29 diverges from I-85 and continues into the central areas of Greensboro, while US 421 joins I-85 from I-73 in a wrong-way concurrency.

Greensboro to Durham I-85 traverses the southern outskirts of Greensboro, with US 421 being concurrent with the interstate in the established duration of . I-85 comes to the diamond interchange with South Elm-Eugene Street, which gives access to Downtown Greensboro, which is miles north of the corridor, alongside the adjacent central areas of the city. I-85 comes to the subsequent large interchange, in which US 421 leaves I-85 in this vicinity. US 421 traverses south to Sanford, while the undesignated stretch to the north connects to the eastern areas of central Greensboro. I-85 maintains its northeastward track, before reaching the interchange for I-785, I-40, and I-840, in which the former and latter of which have their southern and eastern terminus at I-85 respectively. I-40 merges onto I-85 and the two routes share the east–west concurrency for . The two interstates are included in the Piedmont Crescent, while traversing south of the downtown centers of Elon, Burlington, Graham, and Mebane. I-40/I-85 comes to the interchanges with NC 61, NC 62, NC 49, NC 87, and NC 54, and also crosses the Haw River. After coming to the diverging diamond interchange with NC 119 (Mebane-Oaks Road), the corridor exits from Alamance County and enters into Orange County, in which the interstates also comes to another truck weigh station. I-85/I-40 enters into the southern outskirts of Hillsborough, in which I-40 diverges from I-85. I-40 travels southeast into the northern outskirts Chapel Hill, the southern outskirts of Durham, and the city of Raleigh; while I-85 continues northeast into central Durham.