The carrier alleges that both companies misled consumers “by advertising non-existent Ryanair fares via the eDreams website and Google search adverts”.
Ryanair claims that customers have been deceived by misleading subdomains and a copycat website with identical branding.
The decision to pursue court action in Ireland is the latest in a long line of battles with tech companies and so-called screenscrapers.
The carrier is also angry that Google has failed to “enforce transparency” on its online advertising.
Ryanair’s chief marketing office Kenny Jacobs said: "This Google/eDreams action is a repeat of a recently successful German court ruling which has outlawed eDreams deceptive advertising in Germany.
“This deception and mis-selling has led to a surge of consumer complaints and leaves Ryanair with no choice but to take legal action against both Google and eDreams, who continue to use Google search adverts to deceive consumers into booking Ryanair flights on the eDreams website at inflated fares.”
A spokesperson for eDreams said: "The case against Google and eDreams has only just been filed so there is little we can say beyond the fact that we disagree strongly with Ryanair’s position.
"This action is clearly just another attempt from Ryanair to stop Online Travel Agencies from offering consumers the best price and choice when it comes to booking flights."
