Bus drivers working for garages operated by Metroline will strike on seven days next month starting on 1 December.
Londoners are being warned some other bus services and the tube network will be busier as a result of the Unite union action affecting 70 routes.
The action will impact bus journeys mainly in the north, northwest and west of the capital, and most action has been coordinated to take place during other industrial strife from Abellio drivers in south London.
Louise Cheeseman, Director of Buses at TfL, said: “We apologise for any disruption caused to Londoners, especially for people in west London who may be affected by both sets of strike action.”
“There still will be options for people to travel in the affected areas, but other routes may be busier than normal.”
“We’re encouraging everyone in these areas to plan ahead, check before they travel and leave more time for their journeys. Our free TfL Go app and website are really easy ways to check your travel.”
TfL also advised Londoners to check when they travel because the RMT union is also holding strikes on the rail network on Tuesday 13 December to Wednesday 14 December, and Friday 16 December to Saturday 17 December.