NB, please do not rely solely on this information for your travel planning.
From the UK: carriers include Ryanair,
EasyJet, British Airways and Alitalia.
Within Europe: try EasyJet, Alitalia, Ryanair and Meridiana.
By boat from the mainland: you can arrive from Naples, Genoa, Fiumicino, Livorno, Palermo, Trapani and Civitavecchia. The quickest is Civitvecchia to Golfo Aranci (4 hours), the longest Naples to Cagliari (17 hours). They sail into Palau, Olbia, Porto Torres and Golfo Aranci in the north and Arbatax and Cagliari in the south. Car ferries also connect Sardinia with Corsica.