This question should be in Wannabes. However, if you'd looked there in the first place (via the 'search' facility) you would have found that this question has been asked and answered many, many times.
Without going into too much detail (do that search!), in the UK a degree is not necessary and may disadvantage you in terms of time, as Notso suggests. In other European countries, a degree may be required by flag carriers, but in general it is not. In the US, a four-year degree is more or less mandatory if you are not a graduate of the military.
Scroggs