It is hoped the EuroMillions Millionaire Raffle draw will break the record set by last year's 100 Millionaires draw, held on the night of the opening ceremony for London 2012.
On that occasion, 97 of the 100 winners came forward to claim their prize, setting a world record for the number of millionaires made in one night by a lottery draw.
A National Lottery spokeswoman said: "This special EuroMillions Millionaire Raffle draw will see 100 UK players become millionaires on one spectacular night.
"Hopefully we will be celebrating this summer by smashing the record we set last year.
"Players are encouraged to get their tickets early in order to ensure they are in with a chance of joining the National Lottery Millionaires Club.
"The National Lottery has already created more than 3,300 millionaires and we look forward to boosting that number on July 26."
Staff at the National Lottery will keep their phone lines open until midnight on the day, with four times the normal level of staff working to field calls from the new millionaires.
There is usually one winner per draw in the UK, as opposed to the 100 there will be on July 26.