It has never been cheaper or easier to fly to or from Spain. As well as many charter flights and package tours, there are literally hundreds of flights to the mainland and the islands every day of the year.
Before you even book your flight, I would recommend studying a superb web-site www.spanish-airport-guide.com where you will get ALL the information you could ever dream of needing for over 30 airports on the mainland and the islands.It covers transfers, taxis, buses, trains, driving directions, airport shopping, parking, telephone numbers, weather advice, duty-free allowances and arrivals/departures. It really is a superb site and is constanlty being updated.
Here is a list of some of the main operators and airlines. By booking in advance and avoiding peak times, return flights can usually be found at very realistic figures. Many budget operators such as Ryanair and easyJet fly from a large number of UK airports to bigger and smaller airports all over Spain, whilst full-service operators use all the major airports in both countries.
Agencies and portals: