The event begins at 10 a.m. in Kenmore Square. Marathoners are encouraged to wear their race numbers.
“It’s really about the whole running community coming together to support the people who couldn’t finish the race,” said Andy Marx, a #onerun organizer who came up with the idea in the days after the bombing.
The children’s choir from St. Ann’s Parish in Dorchester, where the Richard family attends, will sing the national anthem before the run.
Afterward, runners are encouraged to spend the day frequenting neighborhood businesses.
“The whole intention is to support the Back Bay businesses, and have a feeling of a rolling afternoon,” Marx said.