Alpha Mu Sigma () was an historically Jewish fraternity founded in at Cooper Union. It disbanded in .
Alpha Mu Sigma was founded at Cooper Union on . According to Baird's Manual, "The original plan was to limit membership to men of the Jewish faith and the first expansion was limited to similar engineering institutions." Its founders were:
The fraternity expanded many chapters in the 1920s. However, only a few survived the Great Depression. Its total membership in 1945 was 1,500.
The national fraternity disbanded in , with the remaining four chapters becoming inactive or being absorbed by other, larger Jewish fraternities. Alpha chapter at Cooper Union functioned until .
Alpha Mu Sigma's badge is a black concave shield with the Greek letters vertically in gold with a border of sixteen pearls and sapphires in the corners. Its pledge ben is a black enamel shield, with a jagged white streak through it.
The fraternity's colors are black and gold. Its flower is the yellow chrysanthemum. Its magazine is The Shield.
Following is a list of the chapters of Alpha Mu Sigma, with inactive chapters and institutions in italics.