The change is one of three from manager Arsene Wenger as the Gunners look to finish inside the top four for the 21st consecutive season.
Mesut Ozil and Alexis Sanchez provide the attacking support for Welbeck, while Nacho Monreal moves further up the field to replace Kieran Gibbs in a midfield that also includes Hector Bellerin as a right-winger, a fit Aaron Ramsey and Granit Xhaka.
Once again Wenger opts for a back three and Laurent Koscielny is passed fit after a calf injury to start at centre, with Rob Holding on the right and the returning Gabriel Paulista on the left as Shkodran Mustafi misses out on the matchday squad.
Romelu Lukaku - in search of the golden boot this afternoon - continues up front alongside Valencia and Kevin Mirallas, while Idrissa Gueye, Morgan Schneiderlin and youngster Tom Davies operate in midfield.
Mason Holgate, Ashley Williams, Phil Jagielka and Leighton Baines make up the back four and Joel Robles continues between the sticks, with first-choice stopper Maarten Stekelenburg still sidelined with a groin injury.
Arsenal: Cech; Holding, Koscielny, Gabriel; Bellerin, Ramsey, Xhaka, Monreal; Ozil, Alexis; Welbeck
Subs: Ospina, Mertesacker, Coquelin, Elneny, Iwobi, Walcott, Giroud
Everton: Joel; Holgate, Williams, Jagielka, Williams, Baines; Gueye, Schneiderlin, Davies; Valencia, Lukaku, Mirallas
Subs: Hewelt, Pennington, Barry, Besic, Williams, Barkley, Kone
Keep up with all of the action from the Emirates this afternoon with Sports Mole's live text commentary here.