Real sheep and a donkey will be taking part in a live nativity play, which starts at 4.15pm.
The performance by the Church at the White House School is set to be the high point of the town's first living advent calendar.
Wokingham Town Cllr Dale Green, who has helped co-ordinate the performance, said: "This will be the first time it's in the town centre and we hope there will be lots of people there - the more the merrier.
"It will be a great way to bring in Christmas for families and everyone in Wokingham."
The play has taken place at The White House School, in Evendons Lane, for the last two years, attracting about 300 people each time. Organisers hope at least 500 people will watch this year's performance.
A petting zoo will allow children to meet the animals before and after the show.
Cllr Green said he hopes the nativity will be the "icing on the cake" of the advent calendar, which has seen a different performer entertain residents at 6.15pm every night this month.
He said: "The calendar has been fantastic in bringing vibrancy into the town and by giving local performers the chance to entertain. It's also been a way of supporting local businesses - it's a win-win situation.
"We've had good numbers and lots of different people coming each night."
The calendar is a joint initiative from the Town Council and More Arts and is raising money for four local charities - Wokingham Rotary Club, WADE (Wokingham and District Association for the Elderly), More Arts and JAC (Just Around the Corner).
List of dates and locations for Living Calendar events:
Dec 19 - Herrington Carmichael, 27 Broad Street
Dec 20 - Barbara Easton Ltd, 7-8 Bush Walk
Dec 21 - Waitrose, Rectory Road
Dec 22 - Waitrose, Rectory Road,
Dec 23 - Elms Field, Elms Road - note 4.15pm start
Dec 24 - All Saints' Church, Norreys Avenue