The aim of the 10K run in Regent's Park today is to enable families and friends to remember their missing loved ones and to raise funds for the charity's 24 hour phone line.
Among those taking part will be Missing family representatives Peter Lawrence, father of missing Claudia Lawrence, and Rachel Elias, sister of missing Manic Street Preacher Richey Edwards.
An estimated 250,000 people go missing in the UK every year.
The run begins at 9am on The Broadwalk, Chester Road, Regents Park.
More top news
New research suggests that Londoners often pay twice the price for their houses compared to those who live a short commute out of the city
Seven week old baby sloth Edward, named after Edward Scissorhands because of his long claws, has been given a special teddy at London Zoo
The Met Police are searching for a shotgun-wielding gang of burglars who were caught on CCTV smashing into an East London home