Ryanair has flights from both Edinburgh and Glasgow Prestwick to Alicante. They also fly to Murcia from Glasgow Prestwick. Use the link to the right to check their website for dates and availability.
Easyjet has flights from Edinburgh and Glasgow International (not Glasgow Prestwick) to Alicante. Flights are seasonal and can be expensive. Use the link to the right to check their website for dates and availability
Jet2 has flights from Edinburgh and Glasgow International to Alicante. Use the link to the right to check their website for dates and availability.