Admission to the Sportsground will be free throughout the afternoon - there will be a bucket collection to raise funds for Special Olympics Ireland - and a host of events will take place from 2pm to 5pm.
"It is a great opportunity for children and their families to meet the players and a great opportunity for the players to meet the people who support Connacht Rugby," said Connacht CEO Gerry Kelly.
"It will also be an opportunity to raise funds for Special Olympics Ireland who, time and again, embody all that is good in sport. It promises to be a great day."
Events throughout the afternoon will include bouncing castles, obstacle courses, kicking and try-scoring competitions, while the Connacht players will do a demonstration of skills.
'Eddie the Eagle', the Connacht mascot, will be strutting his stuff but will take a break from showing off to help distribute flags and mini rugby balls.
A full range of Connacht merchandise will be available, while Connacht's sponsors will also have produce available on the day.
Free car parking will be available at the Sportsground on Sunday and supporters, who will have the opportunity to be photographed with the players and get autographs, are asked to arrive early at the Sportsground for what promises to be a day of fun.
And there will be an added bonus for supporters as everyone who attends Sunday's event will be given a free ticket to attend the pre-season game against Rotherham Titans at the Sportsground the following Friday (August 28).