St. Maarten's Princess Juliana International Airport (SXM), which is the second busiest airport in the Caribbean, has flights arriving from many European countries, often routed via Paris. The international airport is on the Dutch, St Maarten, side of the island with l’Espernace airport, which handles the inter island flights, on the French (St Martin) side.
You can also arrive via any of the other Caribbean international hubs such as Antigua or San Juan and take an inter island flight to St Martin.