National Lottery operator Camelot said the £170,221,000.00 jackpot was won by a single ticket-holder on Tuesday.
The ticket-holder is yet to be named and it is unknown if it is a single person, a family or a syndicate.
The winning numbers picked were 7, 10, 15, 44 and 49, with 3 and 12 selected for the Lucky star numbers.
If the winner is an individual, their new found fortune would earn them a place on the Sunday Times' Rich List of the 1,000 wealthiest people living in the UK or with British business links.
According to the paper's 2019 rankings, the winner's wealth eclipses that of singers Sir Tom Jones and Calvin Harris - who are both worth £165m - and Ed Sheeran, who is worth £160m.
The lucky ticket-holder has also beaten the previous record set by Colin and Chris Weir who became Britain's richest lottery winners when they claimed £161m in 2011.
Andy Carter, senior winners' adviser at the National Lottery, said: "One incredibly lucky ticket-holder has scooped tonight's enormous £170m Euromillions jackpot.
"They are now the UK's biggest ever winner. Players all across the country are urged to check their tickets as soon as possible."
1. Colin and Chris Weir, from Largs in North Ayrshire, Scotland, won £161m in 2011, held the record for the UK's biggest ever lottery win.
2. Adrian and Gillian Bayford, from Suffolk, took home more than £148m in 2012.
3. An anonymous UK ticket-holder claimed the £123m jackpot in June.
4. An anonymous UK ticket-holder won £121.3m in April last year.
5. Patrick and Frances Connolly from Northern Ireland won the £114.9m prize in January.
6. An anonymous ticket-holder won £113m in October 2010.
7. Neil Trotter, from Coulsdon, south London, won £107.9m in March 2014
8. Dave and Angela Dawes, from Wisbech, Cambridgeshire, won £101m in October 2011.
9. Ade Goodchild, from Hereford, banked £71m in March.
10. An anonymous ticket-holder bagged £35.2m in April.