The state highway runs 15.63 miles (25.15 km) from U.S. Route 29 and US 50 in Fairfax east to SR 400 in Alexandria.

SR 236 heads east-southeast as Main Street, a four-lane divided boulevard, through a commercial area toward downtown Fairfax.

After three blocks, SR 236 returns to Main Street and continues east as a four-lane divided highway through the eastern part of Fairfax.

[1][2] The state highway passes the Annandale campus of Northern Virginia Community College, whose access road is SR 376 (Lake Drive), before meeting I-495 (Capital Beltway) at a cloverleaf interchange.

SR 236 passes south of the George Washington Masonic National Memorial and crosses over CSX's RF&P Subdivision, which carries Amtrak and Virginia Railway Express service as well as freight service, and the Yellow and Blue lines of the Washington Metro.

Callahan Drive, which intersects the state highway just west of the railroad crossing, provides access to Alexandria Union Station.

Duke Street continues east as an unnumbered road seven blocks to the Robinson Terminal on the Potomac River.

SR 236 appeared in its present location in July 1935 as a replacement for US 50, which for several years previously ran the entire length of the historic Little River Turnpike to Alexandria before turning northward toward Washington concurrent with US 1.