- arm of the Pacific, off the S coast of Mexico: c. 300 mi (483 km) wide
- narrowest part of Mexico, between this gulf & the Gulf of Campeche: c. 125 mi (201 km) wide
- wedge-shaped extension of the Caribbean, between N Colombia & E Panama
- Isthmus of Panama
For names of actual gulfs, see the specific element of the name; for example, Mexico, Gulf of; Lions, Gulf of.