Hair by Sam McKnight has received investment from private equity firm Manzanita Capital to help grow the brand.
The London-based financial company invested an undisclosed sum in the hair care brand during its latest fundraising round.
Manzanita Capital invests in entrepreneurs and emerging brands within the beauty industry, especially luxury and premium niche.
Perfume house Diptyque and skin care company Malin+Goetz sit within its portfolio.
Hair by Sam McKnight was founded in 2017 by celebrity hairdresser Sam McKnight.
He has worked with Princess Diana, supermodel Kate Moss and singer Lady Gaga.
"We are very excited to have secured investment from Manzanita, who are specialists in the beauty market,” McKnight told Cosmetics Business.
“They share our vision to create a brand for the long term, which inspires and educates customers to discover the possibilities of their hair.”
Joel Edmondson, CEO of Hair by Sam McKnight, unveiled the news on LinkedIn on 1 November.
“Hair by Sam McKnight is officially joining the Manzanita family… after closing our latest fundraising round,” he posted.
Sam McKnight is stylist to the stars, with clients including model Gigi Hadid
Edmondson explained that being specialists within the beauty market and having long-term success with brands made Manzanita the perfect partner.
“We know that success is not built overnight,” he said.
“The best products stand the test of time and we value longevity highly, as do Manzanita.”
Manzanita Capital will sit alongside four other new investors in the brand.
Charlotte Tilbury, founder of the eponymous make-up brand, and French fashion designer Olivier Rousteing, have also invested in Hair by Sam McKnight.
Lady Bamford, founder of sustainable beauty brand Bamford, and the Versace family are the other investors.
Hair by Sam McKnight expanded its core at-home dry styling collection this month.
It has added two new hybrid hair care products – Lightweight Cool Girl Superlift Volumising Spray and The Do Blow Dry Style Spray.