Lizzie Jones, the widow of former Keighley Cougars player Danny Jones, will sing Abide With Me before the Challenge Cup final at Wembley.
Wales international Jones died from a heart problem after collapsing during a match against London Skolars in May.
The 29-year-old's widow, a professional singer, will sing the traditional cup final anthem before Hull Kingston Rovers face Leeds Rhinos on 29 August.
"I'm so excited and happy to be able to do something for Danny," she said.
"It is going to be emotional but I'm a professional and can deal with it and I'm doing it for Danny. That'll get me through it."
She added she would use the occasion to thank players, fans and officials for their support since her husband's death.
A trust fund set up by the Rugby Football League Benevolent Fund to secure the futures of the Jones's children - eight-month old twins Bobby and Phoebe - has received donations of more than £230,000.
Danny Jones scored more than 1,000 points in 150 games over two spells with Keighley and played at Wembley in a Four Nations fixture in 2011.
Following his death, the RFL has made heart screening for players at Championship and League One clubs mandatory.