It is hoped the abbey grounds will be a sea of red and white stripes as people get behind efforts to break the record for the largest gathering of people dressed up as 'Wally', the much-loved children's puzzle book character from the Where's Wally? series.
Kirkstall Abbey Development Trust have organised a free Wally's Festival of Fun event to take place at the abbey on Sunday.
At 1pm, there will be a Wally dog competition, with pooches in fancy dress, and this will be followed by the record counting at 2pm.
Adele Rae, community director of the trust, said the current record stands at 4,627.
She said: "I think it's going to be tough to beat but it is something fun for people to get involved with."
The festival, which takes place from 11am until 4pm, will also feature activities and information from local community groups, including improvised comedy, line dancing, yoga and crafts.
Ms Rae said: "The idea of the event is to bring the community together and showcase local groups and what they do.
"It is about celebrating the best of local people and Kirkstall having a a great activism and community, addressing social isolation and improving wellbeing."
A paid entry Jazz at the Abbey event will take place at 7pm in the evening, with the Tom Sharp Jazz Orchestra.