Sigma Tau
ΣΤ
Founded	February 24, 1904; 120 years ago (1904-02-24) University of Nebraska
Type	Honor Society
Former affiliation	ACHS
Status	Merged
Merge date	January 1, 1974
Successor	Tau Beta Pi
Scope	National
Colors	Navy blue and   White
Symbol	Pyramid, Rail Section
Publication	The Pyramid
Chapters	34 (at time of Merger)
Members	45,000 lifetime
Headquarters	United States
[1][2]

Sigma Tau (ΣΤ) was an American honor society in the field of engineering. It was founded at the University of Nebraska in 1904 and merged with Tau Beta Pi in 1974.

Sigma Tau was founded at the University of Nebraska on February 24, 1904 by fourteen faculty members and students in the College of Engineering. Sigma Tau merged with Tau Beta Pi on January 1, 1974.

Sigma Tau's colors were navy blue and white. Its symbols were a pyramid and a rail section. Its publication was The Pyramid.

Membership was chosen from the upper one-third of the junior and senior classes at recognized engineering schools. Selection from those men and women is made on the further basis of practicality and sociability. Approval of at least three engineering faculty is required. Distinguished members of the engineering profession may be admitted as alumni members.