The Lettie Pate Whitehead Evans Administration Building, commonly known as Tech Tower, is a historic building and focal point of the central campus of the Georgia Institute of Technology (Georgia Tech) in Atlanta, Georgia, United States.

Located at 225 North Avenue NW in Midtown Atlanta, it was erected in 1888 as the Academic Building, with classrooms to complement the hands-on training in the adjacent shop building. It was the second edifice completed on the Georgia Tech campus and it is the oldest surviving one.

Tech Tower has achieved local, cultural, and historical significance. Monuments and plaques commemorating philanthropy towards Georgia Tech adorn the building and surrounding landscape. The red brick, Victorian-style building is the architectural anchor of the Georgia Institute of Technology Historic District, a landmark of tradition and school spirit, and the present-day administrative hub of the Institute. It has been the site of many ceremonies and important events, including a visit by U.S. President Theodore Roosevelt and its dedication in honor of Lettie Pate Whitehead Evans, "Tech's greatest benefactor."

Lighted signs spelling TECH hang on each of the four sides of the seven-story central tower, dominating the building's facade and visible from many parts of the Georgia Tech campus and surrounding area. Georgia Tech students have several times stolen the letter 'T' from one of these signs, a prank once tolerated but now strictly forbidden.

In 1887, the state of Georgia acquired 9 acres (3.6 ha) of land from Atlanta pioneer Richard Peters that would form the original campus of what was then called the Georgia School of Technology, as well as the site of its first two structures. The state hired the well-known architectural firm Bruce & Morgan to design an Academic Building, containing "ample accommodations in halls, offices, apparatus rooms, recitation and lecture rooms, free hand and mechanical drawing rooms, library and chapel," as well as a Shop Building, in which "boiler and engine rooms, wood shop, machine shop, forge room and foundry" were located.

Both buildings boasted towers and edifices of similar design. The complementary names and purposes of these buildings reflected the School's founding principles of valuing both theory and practice, while their similar appearance emphasized the equal standing of these principles. Construction work, contracted by Angus McGilvray with his low bid of US$43,250 ($ 1.51 million in 2024), began with the Academic Building in June 1887; the building was completed in September 1888. The Shop Building, completed shortly afterward, was destroyed by fire in 1892 and rebuilt more modestly without a tower. Following this, the Academic Building, later known as Tech Tower, became the oldest building on the Georgia Tech campus, a distinction it continues to hold more than a century later.

On October 20, 1905, U.S. President Theodore Roosevelt visited the Georgia Tech campus. On the steps of Tech Tower, Roosevelt presented a speech about the importance of engineering education. He then shook hands with each of the 500 students present.

Georgia Tech's Class of 1922 installed the famous TECH signs on all four sides of Tech Tower in 1918, giving rise to the building's present nickname. Their purpose, as defined by the donors during their first year at Georgia Tech, was to "light the spirit of Tech to the four points of the compass." The signs were originally made of wood and painted white and gold – the Institute colors. In the 1930s, lightbulbs were affixed to the signs to illuminate them more effectively than the earlier ground-based spotlights. In 1949, the TECH signs were supplemented by neon lighting in metal frames.