Tau Sigma Delta (ΤΣΔ) is an American scholastic honor society that recognizes academic achievement among students in the field of architecture and allied arts.

It was first known as Tau Delta Sigma and continued under that name until the fall of 1914 when it was decided to change the name to the present one there being Greek letter societies already bearing the first name.

[2] As of 1920, according to the constitution of Tau Sigma Delta, the purpose of the society is stated as follows: "It shall be the purpose of Tau Sigma Delta fraternity to unite in a firm bond of friendship, such students of architecture and the allied arts, whose marked scholastic ability, moral character and pleasing personality has shown them worthy of distinction, and to foster and promote high standards of study in the schools and colleges of architecture and the allied arts."

The fraternity's badge is a gold key consisting of the crossed letters, Tau Sigma Delta, a suspension ring at the top, and a pendant at the bottom.

The award is presented annually as a part of the Association of Collegiate Schools of Architecture (ACSA) national meeting.