Championship leader Lewis Hamilton will line up in third after crucially splitting the Ferrari duo with Kimi Raikkonen a place behind.
Max Verstappen should have challenged his Red Bull team-mate for pole, but he failed to complete a single lap in qualifying after crashing out at the high-speed swimming pool section in final practice.
The Dutchman’s mechanics worked furiously to repair the damage on his Red Bull, but they failed to turn his car around in time, and he will start from last place.
Verstappen’s crash in the closing moments of running this morning marked his fifth big error in only six grands prix this season, and his fifth smash in four years in Monte Carlo. Verstappen sheepishly attempted to console his mechanics, but his accident here will only heighten the pressure on the under-fire 20-year-old.
For team-mate Ricciardo, there were no such concerns with the Red Bull car ideally suited to the most famous streets in motor racing.
The 28-year-old Australian has not put a foot wrong, topping every practice and qualifying session this weekend – the first driver to do so this season – and he will now be the overwhelming favourite to convert his pole into a second victory of 2018 with overtaking virtually impossible.
“We sent a statement in practice on Thursday and we have been quickest in every session,” Ricciardo said. “The race is tomorrow and then we will celebrate.
“There is still a lot of fire in this belly. I’ve done everything I can so far, so let’s finish the job tomorrow. I’m pumped. It’s been a good few days.”
Hamilton’s Mercedes team arrived in the Principality fearing the worst at one of their bogey venues, but the Briton, 17 points ahead of Vettel, will take huge comfort from qualifying ahead of Raikkonen at a track where overtaking is virtually impossible.
Hamilton was four tenths down on Ricciardo. Valtteri Bottas was fifth in the sister Mercedes.
“I gave it everything I could,” Hamilton, 33, added. “I was up a little bit on the last lap but wasn’t able to hold on to it.
“It’s still a long race ahead of us tomorrow. I don’t think Red Bull have tried the other tyres yet so it will be interesting to see how we all go.”
Esteban Ocon qualified the best of the rest in sixth ahead of Fernando Alonso, who will start from seventh for McLaren.