Major airlines such as British Airways and Air France and budget airlines such as Easyjet and Air Berlin have regular service between London and Paris. Flying with a budget airline and booking your ticket at least two weeks in advance is usually the cheapest option, and with flights times of a little over one hour, it seems to be the quickest.
However, some factors to consider are that budget airlines usually fly from London airports such as Stanstead and Luton, which are quite a distance from central London; reaching Stanstead by train takes 45 minutes and by car takes over an hour. Even the major airports, Heathrow and Gatwick, are far from central London; Gatwick, for example, is around 65 minutes by car or 30 minutes by the quickest train.
When deciding which way to travel from London to Paris, it is advisable to consider the costs in terms of money and time in getting to the airport from central London--not to mention baggage fees and check-in and security lines.
The high-speed railway "Eurostar" connects London St Pancras station and Paris Gare du Nord, both conveniently centrally located train stations. The journey from London to Paris takes as little as two hours and 15 minutes. In 2009, one way tickets start at £35 when purchased two weeks in advance, which makes them slightly more expensive than budget airlines where prices start around £24. However, unlike airlines, Eurostar does not charge baggage or booking fees. In terms of cost and time, the railway and airlines are comparable, but the Eurostar may be the most convenient.
Paris cannot be reached from London by ferry alone--a train must be taken to the English port of Dover and from the French port of Calais. Traveling this way between London and Paris is very time consuming--it takes around nine hours--and inconvenient, but it does have the advantage of being a scenic route--across Kent and the English Channel. You will also get to see the famous White Cliffs of Dover. Additionally, this can be an attractive option for last minute travelers, as tickets do not need to be purchased in advance. Travel by train and ferry is certainly the slowest route between London and Paris, but it could work out to be the cheapest.
