Stamford Town Council has organised the guest, who it will only describe as "worth his weight in gold". He will switch on the lights at 7pm on Thursday in Red Lion Square.
From 6pm there will be primary schoolchildren singing carols, a live nativity scene, a farmer's market, funfair and Santa will arrive on his sleigh.
Some shops in the High Street will also be opening late night, including Bon Marche and Stamford Post Office, which will be giving away mulled wine and mince pies.
Stamford mayor Maureen Jalili said: "We hope it is going to be more successful than last year.
"It is going to be a real start to the celebrations for Stamford and hopefully the start of a good year for traders.
"It is a good opportunity to get the people and the schoolchildren together for a real community celebration."
The Christmas lights switch-on is the first of a series of events in the town.
There will also be a Christmas Market on Sunday, December 7, and a concert for senior citizens in the town hall on Friday, December 19.
The concert, which features a musical medley, the Welland School of Dance and the Corn Exchange Entertainments Committee, is ticket-only and tickets are available from the town hall.
Stamford Christmas Winter Wonderland will be held on Sunday, December 21, and will feature a variety of festive activities in Bath Row, including games, hog roast, horse drawn rides, vintage fair, classic cars and carol singers.
There will also be an Xmas-factor contest where performers can entertain for three minutes in a bid to win shopping vouchers. Entrants can register on the day.
And until December 31 in council-owned car parks, there will be more time to enjoy the Christmas festivities.
South Kesteven District Council is running a scheme so motorists will be able to stay for one hour more than they have paid for.