Here You can find a list of airlines which operated in Knock airport.
Birmingham International - Ryanair
Bristol - Ryanair
East Midlands - Ryanair
Liverpool John Lennon - Ryanair
London Luton - Ryanair
London Stansted - Ryanair, Pacific Wings
Manchester - Ryanair
London Heathrow - British, Aer Lingus
Milan Bergamo - Ryanair
Faro - Ryanair
Edinburgh - Ryanair
Alicante - Ryanair
Lanzarote Arrecife - Ryanair
Malaga Costa del Sol - Ryanair
Palma de Mallorca - Ryanair, Pacific Wings