There is also a place in the starting lineup for Odsonne Edouard, who replaces Jean-Philippe Mateta in attack alongside Olise and Wilfried Zaha. Eberechi Eze drops to the bench.
Gallagher comes back into the midfield after being ineligible to face his parent club at Wembley, with Jeffrey Schlupp and Cheikhou Kouyaté.
In defence, Nathaniel Clyne starts at right-back instead of Joel Ward, with Joachim Andersen, Marc Guéhi and Tyrick Mitchell completing the back four; Vicente Guaita returns in goal.
Palace have plenty of attacking reinforcements on the bench, including Eze, Mateta, Christian Benteke and Jordan Ayew.
Palace: Guaita (GK), Clyne, Andersen, Guéhi, Mitchell, Kouyaté, Schlupp, Gallagher, Olise, Edouard, Zaha.
Subs: Butland (GK), Ward, Tomkins, Ayew, Eze, Hughes, Mateta, McArthur, Benteke.
Newcastle: Dúbravka (GK), Schär, Joelinton, Shelvey, Saint-Maximin, Targett, Krafth, Wood, Almirón, Burn, Guimarães.
Subs: Darlow (GK), Lascelles, Ritchie, Fernández, Manquillo, Murphy, Willock, Gayle, Longstaff.