ODU may stand for:

• Civic Democratic Union, a former party in Slovakia
• Odigo User File, a file extension used in Odigo Messenger
• Ohio Dominican University in Columbus, Ohio, United States
• Old Dominion University in Norfolk, Virginia, United States
• Operational Dress Uniform, a work uniform of the United States Coast Guard
• Optical channel Data Unit, the digital path layer for the Optical Transport Network (OTN)
• Out-Door Unit, a unit used in microwave transmission

• Odu (disambiguation)
• Odus (disambiguation)