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
Deadly violence has returned to the streets of the capital as a man is stabbed to death in south London.
Two weeks of poignant tributes from family and friends remembering Grenfell Tower fire victims will be heard by the public inquiry.
Train bosses say it will ‘revolutionise’ travel across London and the South East, as a long-awaited timetable transformation is implemented.