Orsa

Orsa or ORSA may refer to:

Places:
 * Orsha or Orša, Belarus
 * Orsa, Sweden
 * Orsa Municipality, Swedish municipality

Vessels:
 * Orsa-class torpedo boat, built for the Italian Navy in the 1930s
 * Italian training ship Orsa Maggiore (A5323), a contemporary ocean ketch serving as a sail training vessel

Other uses:
 * Orsa (moth), a moth in the family Erebidae
 * Operations Research Society of America
 * Own Risk and Solvency Assessment, in EU insurance regulation
 * Oxacillin-resistant Staphylococcus aureus