Sunday’s party is aimed at families and children, ahead of bank holiday Monday’s party for adults.
The events will feature parades, food and music from mas bands, steel banks, soca and calypso, Brazilian music, live stages and sound systems.
The event was first held in 1966 and has become an annual fixture, with two forced cancellations during Covid.
This year, Europe’s largest outdoor festival pays homage to significant anniversaries including 75 years since HMT Empire Windrush docked in England.
It is 50 years since sound systems appeared at the event. The Mas and Sound Systems, the large static units seen at the event, originated in Jamaica in the 1950s, and were introduced to Carnival in 1973.
Stages, food and entertainment can be found in a large area of Kensington and Chelsea, from Ladbroke Grove to Westbourne Park.