The race starts at 9am in front of Belfast City Hall, and motorists can expect delays throughout the morning and into early afternoon.
The 26.2 mile route will pass through all parts of the city before finishing at Ormeau Park.
For spectators wishing to meet family and friends at the finish area, a free park and ride shuttle bus service will run between Ormeau Park and the Belfast City Council car parks on Ormeau Avenue (opposite The Limelight complex) and Cromac Street between 10am and 5pm. This service will operate approximately every ten minutes, depending on traffic conditions.
The area surrounding City Hall will be closed to traffic from 6.30am until 10am, with disruption expected to carry on until around midday.
There will also be delays along the Albertbridge Road, Holywood Road and Sydenham Bypass until shortly after 11am.
As the race moves on, frontrunners will pass back through the city centre on their way to the Falls Road at around 9.40am.
The area around Victoria Street will be disrupted between 9am and 11am.
The four changeover points on the marathon relay route will be impacted, with road closures at Bridge End between 6am and 2pm; Hillview Road between 9am and 2pm; Gideon's Green and Corporation Street between 6am and 3pm.
Disruptions are also expected on the country-bound Antrim Road from 9.45am and 11am, with the runners in a large group along one of the most challenging stretches of the race.
Belfast Zoo will be open as normal.
There are also expected to be delays around Duncrue Road at the Fortwilliam Roundabout off slip, with police and stewards working to keep disruption to a minimum.
Disruption is also expected in Dock Street, while Ormeau Embankment will be closed from 6.30pm until after 5pm.