You must organise a visa in advance to enter Gabon. You will also need the yellow International Health Certificate to prove vaccination against yellow fever, as well as proof of accommodation for at least the first night of your stay.
Your passport must be valid for at least six months from the date of arrival.
Visas are required by all travellers and must be obtained before arrival; they are not available at the airport or at border crossings. Getting a visa for Gabon can be both difficult and expensive. From countries outside Africa it can cost more than US$100. Unless you're flying straight to Libreville from Europe, it may be best to apply for one at the Gabonese embassy in a nearby African country, where it only takes a couple of days and costs around US$60. You will be required to produce a return or onward plane ticket, proof of health insurance and certified proof of accommodation for the first few nights of your trip.
At the Directeur Genérale de la Documentation you can obtain visa extensions.
Visas for Onward Travel
It's possible to get the following visas for nearby African countries in Libreville:
Cameroon Same-day processing; CFA51,000.
DRC Takes 24 hours; CFA50,000; only issued to residents of Gabon.
Equatorial Guinea Takes 72 hours; CFA80,000; only issued to residents of Gabon or people with no EG embassy in their home country.
Republic of Congo Takes 24 hours; 15-day visa CFA30,000, 3-month visa CFA70,000. A hotel reservation is required.
São Tomé & Príncipe Takes 48 hours; CFA13,000.
International Health Certificate
Your yellow International Health Certificate must be produced on arrival in the country to prove you have been vaccinated again yellow fever.