SIX is a service provider for the financial industry and operates the infrastructure of Switzerland's financial center. The abbreviation stands for Swiss Infrastructure and Exchange. SIX develops and maintains securities trading and post-trading platforms and sells cashless payment systems. SIX operates worldwide and is headquartered in Zurich.

Six were a short-lived Irish pop group who formed on the television programme Irish Popstars in 2002. The programme aired on RTÉ One on Sunday nights in the autumn and winter of 2001-02. The band were signed to Simon Cowell under BMG Records UK and managed by Louis Walsh who also appeared as a judge on the show. Their first single 'Whole lot of Lovin' is currently the fastest and third biggest selling single in Irish history.