Children can search for sweet treats and chocolate during the event at the park off Northern Way, Daventry, starting at 3pm on Friday, October 31.
Families are invited to wear Halloween fancy dress and register at the visitor centre to take part in a competition to find the best costumes.
Under fives will then be invited to take part in the Scavenger Hunt for hidden goodies in the country park play area, while five to 12-year-olds can take part in a Trick or Treat Trail around the park.
Children must be accompanied by an adult during the event and will need to bring torches with them as it will be getting dark at that time of the afternoon and there is no lighting in the park.
Families can cut out the coupon in the paper and register.
There will be a free gift for every child.
A coupon can also be found in the September edition of Daventry Calling magazine.
Cllr Alan Hills, community, culture and leisure portfolio holder at Daventry District Council, which has organised the event, said: “The Halloween event we held last year at the country park was very well attended and a big success, with lots of children really getting into the spirit of the occasion and wearing some fantastic costumes.
“This year promises to be no different and it’s completely free to attend so I hope that lots of families can come along during the school half-term holiday and enjoy themselves.” In preparation for the event, there will be a half-term Mini-Adventure at the park’s Visitor Centre on Monday, October 27. Sessions costing £1 per child will be held at 10.30am and 11.20am.