Trans-New Guinea is a family of languages spoken mainly on the island of New Guinea, which comprises the nation of Papua New Guinea and Irian Jaya, Indonesia. With at least 552 languages, the family is one of the most diverse ones in the world. Most New Guineans speak a language in the Trans-New Guinean family.

The name means "Across-New Guinea," so called because its languages are spoken in both the eastern and western parts of New Guinea.