The land boundary between Guinea and Guinea-Bissau extends for 447 kilometers (278 miles) in a northeasterly direction from the Atlantic Ocean to the tripoint with Senegal. It was originally established by French and Portuguese colonial powers in 1886 and demarcated during the early twentieth century. The border line follows a combination of monumented straight lines and rivers, and it has not been adjusted by Guinea or Guinea-Bissau since independence.

Guinea and Guinea-Bissau also have an established maritime boundary.