Wilkins, who passed away on April 4 at the age of 61, played for Chelsea between 1973 and 1979, before moving on to United, where he remained until 1984.
The former midfielder won the FA Cup in 1983 with United, scoring in the final. He also won it thrice with Chelsea later on, when he moved into coaching.
Fans will pay tribute to Wilkins with banners in his memory before kick-off, and he will be honoured in the match programme. Furthermore, his wife Jackie Wilkins will present the trophy to the winner of the cup.
"It is particularly fitting that both clubs and the wider football community will unite to remember Ray Wilkins on the day," said FA chairman Greg Clarke.
"Ray had a longstanding affinity with the competition, winning it as both a player and as an assistant manager. He is sorely missed."