The free family event takes place on Sunday June 5, as the nation celebrates the Queen’s Platinum Jubilee.
Themed as The Great British Picnic, Chorley Council has teamed up with local children’s entertainers to provide celebratory summer fun.
Popular children’s clown Louby Lou will provide the entertainment on the main stage making sure everyone is up on their feet singing and dancing.
There will also be a Punch and Judy show and Paddington Bear will also make a special guest appearances at the event in the park’s walled garden.
Councillor Peter Wilson, Deputy Leader of Chorley Council said: "The Picnic in the Park is a great event for all the family and year after year it's so great to see so many people head to Astley Park for a lovely afternoon out.
"While we cannot guarantee to coax the sun out from behind the clouds, we promise to bring the entertainment for all the family to enjoy.
"This bank holiday weekend, choose Chorley.
"We've not just got brilliant events; we have a thriving and bustling town centre with loads of things to see and do.”
Visitors to the event can also expect funfair rides, a bouncy castle, a soft play centre, a climbing wall and an array of local food and drink sample.
While a whole range of activities will be free of charge, there may be a small fee for some attractions such as funfair rides, bouncy castles, and face painting.