Ogg may refer to:

• Ogg (surname)
• Nanny Ogg, a character in the Discworld series of books
• Ogg, a multimedia container file format, in computing
• Ogg Vorbis, the Vorbis free software/open source audio codec, commonly used with the Ogg container
• Kahului Airport's IATA code
• Ogg (Cro character), in the Children's Television Workshop animated television show
• Ogging, an online computer gaming tactic
• Oud Gereformeerde Gemeenten, a pietistic Reformed denomination in the Netherlands
• Operation Good Guys (OGG), a British TV mockumentary series
• Original Gospel Gangstaz, Christian hip hop group
• Oxoguanine glycosylase, a DNA glycosylase enzyme

Ogg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high quality digital multimedia.