Emma Wilson Urban Spa on Streatham High Rd. It’s so tranquil, a real gem and I can assure you that you won’t be disappointed.

Claudalie in Northcote Road

If you're after a spa and treatment or just me time - try Spa London in wimbledon - their snooze area is lovely very after a sauna and soak in jacuzzi plus nice range of Wibble teas fruit and magazines
its not high end but certainly favourable and local
https://www.spaexperience.org.uk/locations/wimbledon

Any recommendations for beauty / spa places in Balham or nearby?