The front page of Germany's Frankfurter Allgemeine Zeitung has the headline "Storm over London", above a picture of a High Court judge with his wig flapping around in the air.
"Judges put the brakes on Brexit," reads a front-page headline in Italy's Corriere della Sera, La Repubblica has "Brexit: Surprise ruling", and French business paper Les Echos says "Brexit: London's dramatic turn of events".
For Frankfurter Rundschau's London correspondent, Sebastian Border, the decision is "a heavy blow for May's government", and he sees the Brexit schedule "faltering".
The Hungarian tabloid Blikk believes the latest developments are worthy of Shakespeare, with the headline "To Brexit or not to Brexit, that is the question - parliament will decide".
French paper Les Echos, says Theresa May's government "hit an iceberg called the High Court of Justice". "Enough to sink the Brexit ship? Or just rock it slightly?" it wonders.
An article in German tabloid Bild shows a picture of a kissing couple bearing EU and Union Jack face-paint, along with the headline "Is this the exit from Brexit?"
But few commentators believe the ruling is likely to overturn June's referendum result.
L'Express describes the ruling as a "thunderbolt from across the Channel", but adds that although a delay is now likely, Brexit will still go ahead in the end.
In Italian business daily Il Sole 24 Ore, London correspondent Leonardo Maisano, says the High Court "detonated a new bomb" under Brexit, but believes MPs will ultimately not go against the "popular will expressed in the referendum".
Instead, most think the ruling only complicates an already tricky situation even further.
"Here comes the big mess," declares a headline in Germany's Zeit, whose London correspondent, Sascha Zastiral, describes the ruling as "a severe setback" for Theresa May's Brexit plans.
France's Liberation sees the decision as "not a setback for Brexit, but a stinging rap on the knuckles" for the government.
In Frankfurter Allgemeine Zeitung, London correspondent Marcus Theurer writes that this "bitter defeat" for the PM and Leavers will "poison the political debate" in the UK, and increase the "uncertainty around Brexit even further".
Spain's El Pais also highlights the unprecedented nature of the situation, which it says takes the country into "the tricky uncharted waters of Britain's unwritten constitution".
Italian paper Il Messaggero describes the ruling as "a spoke in the wheels of Brexit" and emphasises that it is hard to predict what will happen next, as we are now "in completely new territory".
"It is not by chance that Collins dictionary has chosen 'Brexit' as the word of the year," it concludes.
BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring  on Twitter and Facebook.

Keighley MP Kris Hopkins has written to police asking them to investigate.
An audit by PKF Littlejohn LLP found the council had made decisions "without consideration of its legal powers" and may have taken "unlawful actions".
The council's decision to develop a new civic centre came in for heavy criticism in the audit report.
Auditors said the council may have broken the law by trading via the civic centre museum shop.
The audit also picked up on "mathematical errors" in budget documents which "could potentially have influenced decisions made in respect of funding required for 2013-14".
In response to Mr Hopkins' letter, West Yorkshire Police's temporary chief constable Dee Collins said investigators from the economic crime unit would be contacting the auditors.
She said: "Once this review and assessment is completed, we will be in a stronger position to understand if any criminal offences have taken place within the town council."
Mr Hopkins said: "I have been a long-standing critic of Keighley Town Council and, alongside a number of tireless and committed local residents, have raised countless concerns about its reckless and arrogant approach to spending public money.
"This report confirms in graphic detail that our fears were well-founded."
Keighley Town Council said it had received independent legal advice that found the council had not acted outside the law.
Mayor Graham Mitchell added: "There is no evidence of criminality whatsoever in the report."
European press commentators have been taken aback at the UK High Court's ruling that Parliament must be consulted on Brexit, with many predicting further uncertainty for the UK and the rest of Europe as a result.
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Keighley Town Council could be investigated by the police after an audit found "significant weaknesses" in local governance.