Getting to Estoril from the Lisbon Airport:

Using public transports

Use the bus service nº91 from Carris, that goes from the airport to the CP Cais do Sodré train station. In this station you will have access to the Cascais line that serves the Estoril Coast. Departures happen every 20 minutes, from 6 AM until 1 AM.

Taxi:

You may also pot for the Taxi. Seek, just outside of the Lisbon Airport, one of the many Taxis available to take you to your destiny - Estoril Coast.