Ryanair used to have flights to Balaton Airport in Hungary which was only about 60 km or so from the Croatian border, and was very useful to those trying to reach northern or eastern Croatia. They no longer operate this route and there are no other flights from the UK or Ireland to this destination.

There are still however flights to Budapest from various British airports. On one hand, flying to Budapest is suitable as there are many flights from British Airports by various airlines. However, in all honesty, Budapest isn't really an ideal place to fly to if you're trying to reach Croatia - if you're not flying directly to the country, flying to Italy, Slovenia or Austria (depending on what your final destination is) is a much better option!

Nevertheless, here's some information on how to reach Croatia from Budapest.

Travelling from Budapest to Croatia
There are several direct trains per day from Budapest Keleti station to Zagreb. The journey takes between 6 and 6 and a half hours. From Zagreb, you can then take a train or bus to your required destination in Croatia.

See the Die Bahn website for the best information about train timetables.

Useful Travel Links
Ryanair Flights from Bristol, East Midlands, Liverpool, Glasgow and Dublin to Budapest
Easyjet Flights from London Luton and Gatwick to Budapest
British Airways Flights from London Heathrow and Gatwick to Budapest
Jet2.com Flights from Manchester
WizzAir Flights from London Luton
Budapest Airport Including information on travelling between the airport and downtown Budapest
Die Bahn Train timetables for journeys from Hungary to Croatia
Hungarian Railways Also provides timetables for routes from Hungary to Croatia