Honoré joins after spending the past couple of months on the squad as a stagiaire, with his results and work-rate impressing sufficiently to earn him a two-year deal with the winners of this year's UCI WorldTour teams classification, with the Belgian squad winning 73 races during the 2018 season.
The 21-year-old Dane was never expected to add to that win tally, but nevertheless recorded some impressive results in Quick-Step colours, including 12th place at the Grand Prix d'Isbergues in September and 11th at the Binche-Chimay-Binche at the start of October.
Perhaps more importantly, Honoré impressed with his work for the team, and was able to help Philippe Gilbert to win the GP d'Isbergues, which was the Belgian veteran's comeback race from the fractured kneecap he'd suffered at the Tour de France.
Quick-Step Floors team boss Patrick Lefevere was already impressed by Honoré's attitude and abilities at under-23 level, and trialling him as part of the team for the latter part of the season only cemented what he already knew.
"Mikkel's quality, talent and maturity surfaced not only in the U23 ranks, but also when riding against the pros, in such races as the GP d'Isbergues and Binche-Chimay-Binche, which weren't a stroll in the park, so offering him a contract was the logical step to take.
"We welcome him to the Quick-Step Floors family and hope we'll have a fruitful relationship over the next couple of seasons," Lefevere said on the team's website.
Honoré joins the team from the Bjarne-Riis-owned Team Waoo Continental team, which changed its name from Team Virtu Cycling just prior to this year's Tour of Denmark in September.
"It's a childhood dream come true to sign with Quick-Step Floors," he said. "I was given the chance to ride here as stagiaire in the last months of the season, which has been really cool, and I've enjoyed every moment, but I didn't dare to dream of signing a contract, so this is truly an amazing feeling.
"Everybody has been super-welcoming, which made the experience even better and made me feel at home from the first meeting."
Honoré will be one of three Danes on next season's squad, alongside Kasper Asgreen – who joined Quick-Step from Team Waoo this season – and current Danish road race champion Michael Mørkøv, as well as directeur sportif Brian Holm.
"First of all, I'm looking forward to meeting the whole team during the off-season training camps and getting some good winter training under my belt to be as ready as possible for the 2019 season, where I hope to continue where I left off and prove myself worthy," Honoré said of his plans for next year.
"I'm not setting any specific goals for now. I'm just keen on learning as much as I can from all the experience my teammates and staff can offer.
"I can't think of a better platform for continuing my development over the next years than the one I am being offered at Quick-Step Floors," he said.