Attendees can explore stalls selling rare, retired LEGO sets and the latest releases, as well as dedicated minifigure stalls.
Activities for children include a play area with hundreds of LEGO bricks where families can have fun together.
Chris Hone, chief operating officer for Doncaster Culture and Leisure Trust, said: “We are looking forward to welcoming LEGO fans to Doncaster Dome in March.
“We’re sure that lots of families will rediscover the joy of building, creating and enjoying LEGO.”
The event will feature more than 20 traders and skilled LEGO builders. Chris added, "This is a perfect Sunday activity for families, LEGO remains popular with all ages and never seems to go out of fashion."
For tickets and entry times visit www.nationalbrickevents.co.uk/event/doncaster#tickets-section