S London 6th form recommendations?

[CaroBeaner]

Where would you look for a boys or co-ed sixth form for a science (probably Maths, physics and chemistry) orientated student who is likely to get A , A* in A level subjects and English at GCSE and generally As and Bs.
State sector. We have no faith involvement but would not object to a faith school.
How do sixth forms assign places? Is distance a factor? We are in the Southwark / Lambeth / Croydon / Wandsworth area.

Sutton Grammar? Wallington? Graveney?

Graveney's got the biggest sixth form in the area which has its pluses and minuses. The pupils who do best (and they have plenty of A*s, As and Oxbridge/Russell group entries) are motivated self-starters (I think it's quite easy for quiet, lazy ones to get 'lost' in such a big environment)

Check what the admissions criteria are - but the sixth form doesn't have a catchment in the same way as for Y7 entry

You might take a look at Greycoats which takes boys in the sixth form and Pimlico Academy. Both in Westminster but fairly accessible from much of South London. Pimlico has improved a lot over recent years and its sixth form has a good reputation.

That's interesting - I didn't know it was possible to go to the Sutton grammars for sixth form if you hadn't been a pupil there.
Graveney will be on our list, and Dunraven which seems to have a rising-fast reputation. We will look at Greycoats and Pimlico, too. We start looking next year.
I had a quick look across the prospectuses but the admissions criteria don't seem to be clear, cut and dried like the procedures for secondary transfer.

Prendergast gets soe excellent Science results.

some!

It might also be worth adding the Harris Westminster sixth form to your list. Brand new so will be interesting to see if reality matches aspiration.

So would a school like Prendergast take new students based on GCSE results?

Prendergast does take on students to the sixth form, based on their GCSE results. It is an expanding sixth form too, so taking more on roll every year.