The park, which has undergone a £1m restoration thanks to a Heritage Lottery Fund grant, will host the May Day and Market in the Park events take place on Monday 6 May from 10am to 3pm.
More than 6,000 people attended in 2018 and the organisers, South Kesteven District Council and the Wyndham Park Forum, are aiming to beat that number.
A spokesperson for SKDC said: "We had tremendous feedback after the success of last year's celebrations and have responded by adding even more attractions for the whole family."
New for this year will be a crafts market, inflatable climbing wall and bouncy castle, outdoor tennis and table tennis, model tanks and model boats.
Popular crowd-pleasers returning include Grantham School of Dance, the Clifton Maids and the Lincoln and Micklebarrow Morris Men.
Entry is free, including the market and dance displays. Charges apply for some activities.
Visitors can have a go at guessing the name of a Jellycat Swan, with the winner taking it home. Tickets are on sale in the Wyndham Park Visitor Centre and the winning name will be drawn at 2pm.
For more information go to www.wyndhamparkgrantham.co.uk
For media enquiries: Email the SKDC communications team at firstname.lastname@example.org or phone 01476 406498 or 406440.