Italian competition authority, the AGCM, found both carriers supplied misleading and inadequate information to consumers.
The authority imposed an €850,000 on Ryanair which was given 30 days to say how it will change its “unfair commercial practices”.
EasyJet received a smaller fine of €200,000 as it had complied with a request to make changes.
The authority criticised Ryanair for its “unfair, cumbersome and misleading” practice of opting customers into buying travel insurance.
Ryanair said it would appeal the ruling while amending its website to comply.
EasyJet expressed disappointment at the fine, saying all of the issues raised “have already been remedied”.