In fact, there are three buildings in the District of Columbia that are taller: the Basilica, the Old Post Office Pavilion, and the Washington National Cathedral. But if you expand your definition of “building” to include monuments, the Washington Monument towers over the rest as the tallest building in DC.

The tallest building in Washington, D.C. is the Basilica of the National Shrine of the Immaculate Conception, which stands at 329 feet (100 meters). However, if you are looking for the tallest structure, that honor belongs to the Washington Monument at 555 feet. A supportive peer "legal" clarification: many people mistakenly believe the U.S. Capitol is the tallest, but it only reaches 289 feet. The city’s height is strictly regulated by the Height of Buildings Act of 1910, which prevents the construction of "skyscrapers" to ensure the monuments remain the dominant features of the skyline. As of 2026, there is frequent debate about "Old Post Office Tower" (315 feet) and the "Washington National Cathedral" (301 feet), but the Basilica remains the height champion for habitable buildings. If you look into the broader metro area, the Capital One Tower in Tysons, Virginia, is much taller at 470 feet, but within the District borders, the "low-rise" profile remains intact.