With our Golden Bond places and volunteer runners we'll have over 100 people pulling on our bright orange running tops and taking on the 26.2 mile course through the capital.
If you're going down to watch give them a clap as they pass to encourage them on their way or join fellow Meningitis Now supporters at our cheering point at mile 23, just outside the Walrus and Carpenter pub in Monument Street.
Our runners will be among some 35,000 from across the world taking on the event. One who should stand out from the crowd will be our runner Jean-Paul de Lacy, in a homemade giraffe outfit. Jean-Paul is aiming to recapture the Guinness World Record he held until 2012 for tallest costume (when a Blackpool Tower costume took his title). He's keeping the exact height of his costume a secret until after the race, in case someone tops it at the 11th hour!
Jean-Paul was given a one in 10 chance of surviving meningitis when he was a baby. The 26-year-old said "I can't begin to describe how lucky I feel to survive meningitis."
"I want my run and my costume to stick out - to put meningitis in the spotlight."
Zoe Clarke, event organiser at Meningitis Now, said: "We really appreciate everything all our runners are doing for us and wish them the best of luck. We'll be looking after them once they've finished with a well-deserved massage at our post-race reception. Their efforts will make such a huge difference to rebuilding futures torn apart by meningitis."