The stars of Waitress' West End production will appear alongside one another at the Phoenix Arts Club.
Presented by Lambert Jackson Productions, the event will stream online on 23 August at 5pm.
Tickets are available to purchase online here NOW up to 4PM on the day of the performance.
The news comes on the day of what would have been the closing night for Waitress in London. The show ultimately ended its run in March when theatres across the UK shutdown.
A teaser for the concert reads: "You’ll have the best seats in the house, whilst experiencing a fully virtual, safe, live experience.
"Waitress on the West End may have closed early, but Lucie and David couldn’t miss this opportunity to get together and sing some of their favourite tracks, both new and old."
Hunter and Jones said: "After we were robbed of our glorious reunion and an emotional closing night at Waitress The Musical we've decided to put things right and perform one more time.
"So buy your tickets today and enjoy us for an evening of songs from some of our favourite shows, including She Used To Be Mine."