This year's theme is 'superheroes'.
Mask-making workshops on Lower Marsh from 12 noon before the procession leaves Tanswell Street at 1.30pm for a 2pm finale at Waterloo Millennium Green.
There will be more activities and music on the green through the afternoon, whilst the party continues outside Cubana till 8pm.
For the latest local news and events direct to your inbox every Monday, you need our weekly email newsletter SE1 Direct.