River Island is a London-headquartered high street fashion brand, which operates in a number of worldwide markets. Set up in 1948, by Bernard Lewis and his brothers in London, River Island is a private company owned by the Lewis family.
In 1948, Bernard Lewis started selling fruit and vegetables, and then knitting wool from a bombed-out site in the East End of London.  Joined by his three brothers,  the chain expands to nine stores under the title Lewis Separates. 
By 1965 Lewis Separates had an impressive 70 store empire in the UK and it was decided that the brand needed a new identity. Lewis Separates was re-branded to Chelsea Girl,  the name chosen because at the time the King's Road in Chelsea was the hub of fashion, music and popular culture.  Chelsea Girl became the first UK fashion boutique chain.
In the late 1970s, two of the brothers left the business,  leaving Bernard, David and their families in charge. They formed the Lewis Trust Group, for which David ran the other businesses covering hotels, property and investments, leaving Bernard to run the retail operation. This allowed the company to expand into menswear in 1982 with the launch of Concept Man stores,  before they were merged with Chelsea Girl to become one retail brand under the name of River Island in 1988. 
In 1993, the brand opened its first shop in Republic of Ireland. Since then it has expanded into a dozen markets including Russia, Poland, and various countries in the Middle East.
In 2010, River Island launched Kidswear. In 2011, Chelsea Girl was re-introduced as a capsule collection within River Island stores. 
River Island has over 350 stores in the UK, Ireland, Asia, the Middle East and Europe alongside 6 online websites that operates in 4 currencies, which ships to over 100 countries worldwide.
As of 2012, River Island no longer has physical shops in Singapore. In 2013, online fashion retailer Zalora began acting as a bridge between River Island and most of South-East Asia. 
In this season River Island will open three stores in Chile:
- Los Condes Santiago
- Costanera Center Santiago
- Parque Arauco Santiago
River Island in Peru is planning to open two stores in :
- Jockey Plaza Lima
- Miraflores Lima
The number of River Island stores on 18 November 2016:
River Island has an in-house design team at its West London Headquarters.