British five-time Olympian Jo Pavey will run in this year's London Marathon.
Pavey, 43, set a personal best of two hours 28 minutes 24 seconds when she ran in the event in 2011.
"I wanted to be sure I was injury-free and could crack on with my training before committing," she said.
Jemima Sumgong will defend her title on 23 April, with world champion Mare Dibaba and two-time winner Mary Keitany also in the field.
Kenya's Sumgong, 32, recovered from a heavy fall to win the race last year, then claimed Olympic gold in Rio.
The elite line-up also includes Florence Kiplagat, who won last year's Chicago Marathon, Tokyo Marathon champion Helah Kiprop, and Olympic 5,000m champion Vivian Cheruiyot, who will make her marathon debut aged 33.
Pavey, who hopes to compete at the World Championships in London in August, said: "I know it's a tough ask, but it is an exciting challenge to think about the possibility of representing my country over distances from the 1,500m right up to the marathon."
She won gold in the 10,000m at the 2014 European Championships in Zurich.
Meanwhile, Tsegai Tewelde, who was born in Eritrea and lives in Glasgow, has been added to the men's field for the London Marathon.
The 27-year-old hopes to win a place in the Great Britain team for the World Championships.