Ratcliffe graduated from the University of Birmingham with a degree in chemical engineering in 1974.
In 1985, Ratcliffe married Amanda Townson, they had two sons, and divorced in 1995. Ratcliffe has one daughter with his second wife, Alicia.
Ratcliffe was a co-founder of INSPEC, which leased the former BP Chemicals site in Antwerp, Belgium. In 1998 Ratcliffe formed Ineos in Hampshire to buy-out INSPEC and the freehold of the Antwerp site.
From this small base, using high-yield debt to Finance deals, Ratcliffe started buying unwanted operations from groups such as ICI and BP, selecting targets based on their potential to double their earnings over a 5-year period. In 2006 Ineos bought BP's refining and petrochemical arm Innovene, giving Ineos refineries and plants in Scotland, Italy, Germany, France, Belgium and Canada.
Ratcliffe enjoys skiing and sailing, and is also reported to have completed the 2007 London Marathon.
In May 2009, Ratcliffe was granted an honorary fellowship by the Institution of Chemical Engineers citing “his sustained leadership in building the Ineos Group.” In 2013 he received the Petrochemical Heritage Award.
In April 2010, Ratcliffe moved Ineos's head office from Hampshire to Rolle, Switzerland, decreasing the amount of tax the company paid by £100m a year.
Ratcliffe has owned two super yachts, Hampshire and Hampshire II. His first yacht was built as Barbara Jean by Feadship. In 2012 he took delivery of the 78 metres (256 ft) Feadship Hampshire II, built by Royal van Lent, which he still owns.
In 2015, Ratcliffe opened the UK headquarters of the chemicals and Energy group in Knightsbridge, London along with gas and oil trading, and other functions, saying he was "very cheerful about coming back to the UK”. He was pleased with UK policy, London as a Business base, and untroubled by the prospect of the UK leaving the EU. "For the time being" it remains an Anglo-Swiss company. It retains a head office in Rolle Switzerland for businesses in INEOS Group AG. The Anglo/Swiss Business continues to grow. Full year 2015 EBITDA was €577 million compared to €253 million for 2014.
He lives in Chelsea, London, and Hampshire, England. In May 2017, he submitted his fifth plan, less ambitious than the first four, to build a "luxury home" at Thorns Beach, near Beaulieu, on the Hampshire coast, which would replace an existing two-bedroom bungalow.