U.S. Route 29 (US 29) is a north–south United States highway that runs for 1,036 miles (1,667 km) from the western suburbs of Baltimore, Maryland, to Pensacola, Florida. This highway's northern terminus is at Maryland Route 99 in Ellicott City, Maryland. Its southern terminus is at US 90 and US 98 in Pensacola, Florida.

The section of US 29 between Greensboro, North Carolina, and Danville, Virginia, has been designated as Future Interstate 785 and has received "Future Interstate" signs in several locations along that route. It will become an official Interstate Highway once improvements have been completed.

From Greensboro, North Carolina to Tuskegee, Alabama, Interstate 85 (I-85) runs parallel with US 29, which along that stretch, serves primarily as a local route.

US 29 begins at U.S. Route 90 and U.S. Route 98 in downtown Pensacola, Florida. Throughout the state, U.S. 29 is twinned with the unsigned State Road 95.

The entire route in Florida runs within Escambia County. From its terminus north to State Road 296, it is known as North Palafox Street. From this point it is known as Pensacola Boulevard north to Ten Mile Road, approximately one mile north of U.S. 90 Alternate. Between SR 296 and the Molino community, U.S. 29 runs parallel to its former routing, which is now Escambia County Road 95A. This former routing continues the name North Palafox Street from SR 296 north to Ten Mile Road.

US 29, internally designated by the Alabama Department of Transportation as State Route 15 (SR-15), is a southwest-northeast state highway across the southeastern part of the U.S. state of Alabama. SR-15 ends in Brewton at a junction with US-31 (SR-3) and SR-41, but US-29 continues west with US-31/SR-3 to Flomaton and south on SR-113 to the Florida state line.

U.S. Highway 29 and SR-15 traverse Alabama in a general northeast/southwest slope. It has never been a major route in the state; its significance was completely overshadowed with the completion of Interstate 65 and Interstate 85 during the 1970s. Today, US-29 and SR-15 serve primarily to connect numerous smaller towns and cities in the southwest, south-central, and eastern parts of Alabama, notably passing through Auburn University and near Tuskegee University in the east.

US 29 passes through the northern portion of Georgia, serving Atlanta and Athens. The highway passes by notable universities, such as Georgia Tech and Emory University in Atlanta and the University of Georgia in Athens. US 29 also meanders through Hartwell and the Lake Hartwell region near the South Carolina border. From West Point, Georgia (Just south of LaGrange, Georgia) at the Alabama-Georgia Line to downtown Atlanta, Georgia State Route 8 and Georgia State Route 14 are paired with US 29 at various points in the state. US 29 to the southwest of Atlanta has been named Roosevelt Highway, since FDR made his final journey northward from Warm Springs along this stretch of highway. Large crowds gathered along US 29 on this day in April 1945 to pay their final respects to the deceased President.

In South Carolina, US 29 maintains a northeasterly routing, passing through Anderson, Greenville, and Spartanburg.

From Greenville through Greer, US 29 is known as Wade Hampton Boulevard. It is a major commercial artery for both Greer and Taylors. A six-lane highway, the road forms the western border of Bob Jones University and then passes near Chick Springs, a mineral springs that served as the focus of a small but important resort community during the nineteenth century.

US 29 was built as the main highway between Greenville and the other city of northwestern South Carolina, Spartanburg. The construction of Interstate 85 connecting Greenville to Spartanburg left US 29 underused until recent decades.

In North Carolina, US 29 connects the cities of Charlotte, Concord, Gastonia and Greensboro. US 29 routes through Charlotte along Tryon Street, one of the main arteries that runs through uptown Charlotte.

In Virginia, part of U.S. 29 is named the Lee Highway. U.S. 29 connects the historic small cities and large towns of west-central Virginia, including Danville, Lynchburg, Charlottesville, Culpeper, Warrenton, Manassas, and Fairfax, with Arlington, and Washington, D.C., to the northeast, and with North Carolina to the southwest.

Along its route in Virginia, U.S. 29 provides significant access to and from several major colleges and universities, including the University of Virginia in Charlottesville, George Mason University in Fairfax, Sweet Briar College in Sweet Briar, and Liberty University, Lynchburg College, and Randolph College in Lynchburg.

US 29 enters Washington, D.C., via the Francis Scott Key Bridge adjacent to Georgetown University. The designation turns east onto the Whitehurst Freeway, bypassing Georgetown to the south. Upon crossing Rock Creek, the freeway ends, becoming the at-grade K Street. US 29 remains on K Street to 11th Street, where US 29 turns north onto 11th for seven blocks. At Rhode Island Avenue, US 29 turns right. US 29 northbound turns left at 6th Street NW (touching US 1 where it turns from Rhode Island Avenue to 6th Street); it follows 6th Street NW for two blocks and then turns left onto Florida Avenue NW, where it then turns right onto Georgia Avenue NW. US 29 southbound at this point, however, follows 7th Street, NW to Rhode Island Avenue NW. The route maintains a northerly routing as it passes through northern Washington, D.C. and enters Maryland. During its alignment with Georgia Avenue NW, US 29 bypasses the Howard University campus to the west.

In Maryland, US 29 turns northeast onto Colesville Road, interchanges with the Capital Beltway (Interstate 495), becomes Columbia Pike, and interchanges with New Hampshire Avenue (Maryland Route 650), Maryland Route 200 (known as the Intercounty Connector), Maryland Route 198, Maryland Route 32, Maryland Route 175, Maryland Route 100, US 40 and I-70 before terminating at Maryland Route 99 northwest of Ellicott City. There are plans to extend the northern terminus to Taneytown, near the Pennsylvania-Maryland border.[citation needed]

Warrenton Turnpike is the former name of US 29 through Prince William County, Virginia. This is the name that was used for this road during the Civil War. Although the road has been expanded past Manassas into four lanes, it remains a rural two lane highway through Manassas National Battlefield Park, where Interstate 66 carries through traffic. On either side of the road through the battlefield, split rail fences define property borders.

The portion of US 29 from US 70 at Charlotte, North Carolina northeast to Lynchburg, Virginia was U.S. Route 170 from 1926 until 1931, when US 29 was extended over it.