The Three Lions boss last week made the decision to name a provisional 33-man squad rather than his final 26-strong selection due to players’ injury concerns and continental cup final commitments.
Southgate has now finalised his Euro 2020 selection, trimming six players after Mason Greenwood withdrew through injury on the morning of the announcement.
Lingard, Ward-Prowse and Watkins missed out along with the uncapped trio of Aaron Ramsdale, Ben Godfrey and Ben White.
Lingard’s outstanding start to life on loan from Manchester United at West Ham saw him brought in from the cold in March’s World Cup qualification triple-header.
The 28-year-old played a part in all three of those matches but Southgate indicated in the build-up that he was there due to the absence of the injured Jack Grealish and Jadon Sancho.
Southampton skipper Ward-Prowse played in two of those games and had been due to start the third until withdrawing through injury and has missed the cut, as he did for the 2019 Nations League finals.
Aston Villa striker Watkins scored on his debut against San Marino but was behind Harry Kane and Dominic Calvert-Lewin in the pecking order.
Alexander-Arnold was selected as one of four right-backs, joining Kieran Trippier, Reece James and Kyle Walker in the 26-man squad.