No visa is required by nationals of most countries although they may be strict in enforcing that you have a return/onward ticket and sufficient funds for your stay.
Nationals from Afghanistan, Bangladesh, Iraq, Iran, Laos, Mali, North Korea, Libya, Mali, Pakistan, Palestine, Somalia, Sudan, South Sudan, Syria and Yemen must have a visa prior to arrival.
Everyone else either needs no visa or can buy a visa on arrival at the airport.
Mauritius - Visa Information
Mauritius embassies
