Summer camp?

[PeloMom]

Can anyone recommend summer camp (not sure if that’s what’s called in the UK) or similar in/around Gloucester Road area (London) for a 4year old? Our family will be in London for a few weeks in the summer and we’d like keep kiddo socialized. Where do people send their preschoolers in the summer?

They generally don't. They spend time with them, or, if they are at work, then they will be in their Nursery if that is where they normally go.
Very rare for Out of School Provision to take pre-schoolers.

Yeah I don't think you would find camps for kids so young. You might get them in a day care nursery if their regulars are going on holiday though.

You might have a Camp Beaumont near to you,
They take 3-5yos in their youngest group.

Playball Camps are perfect for 4 year olds!

playballlondon.com

Supercamps takes four year olds as long as they're in school reception: not sure how that would translate to your DC if they're in a different (US?) system.
There's one in Knightsbridge.
www.supercamps.co.uk/Venue/Princes-Gardens-Preparatory-School