Verstappen's mistake marked his fourth crash in as many seasons at the principality.
Two years ago, that still didn't deter the young Dutchman, who climbed through from 21st on the grid to run inside the top 10 in the mixed conditions, before crashing out at Massenet as he ran wide into the barrier.
Verstappen's speed and gung-ho style have seen him earmarked as a future world champion, but his accident at the high-speed swimming pool section was his fifth major error in six rounds this year, and his fifth crash in four appearances in Monte Carlo.
Verstappen's failure to make it out in time for qualifying came after it emerged shortly before the session got underway that there was a problem with his gearbox.
"I feel we set as much of a benchmark as we could", said Ricciardo, who won the Chinese GP last month.
"The auto felt good in some places, in others it felt bad", said Hamilton.
Verstappen's Monaco resume is less impressive than the Australian's, and he has also been heavily criticised this term after botched overtaking manoeuvres ended his chances of winning in Shanghai.
Asked how he explained his propensity for trouble, he said: "At the moment, I can't". At the Spanish Grand Prix he also lost part of his front wing against Lance Stroll's Williams, but went on to score a podium by the end of the race. I gave it all I could.
"I think the whole thing has been blown up, unnecessarily".
A lap record of one minute, 10.810 seconds saw Ricciardo finish top of the pile and he will be joined on the front row by Sebastian Vettel, with championship leader Lewis Hamilton - victor of the last two grands prix - only able to take third.
"I'm very surprised because I know how incredible Mercedes is", said the retired German.
Daniel Ricciardo punched the air and saluted the Monte Carlo crowd as he crossed the start-finish line, secure in the knowledge that he will start from pole position when the five red lights go out to start the race at 5.10pm UAE time. "There is still a lot of fire in this belly".