After agreeing a loan until the end of the season this afternoon, the Everton forward is registered and has been given a place on the substitutes’ bench.
He is eager to begin his time in Scotland in front of the Sky Sports cameras in one of the biggest fixtures on the calendar.
Hearts manager Robbie Neilson and sporting director Joe Savage identified 21-year-old Simms as a player who could strengthen their attacking options.
With Armand Gnanduillet and Jamie Walker both gone, the stage is set for the new arrival to make an impact.
“I’m really happy to get a player of Ellis’ quality on board,” Neilson told the Edinburgh club’s official website. “We’ve made no secret of looking for a striker and in Ellis we’ve found what we’ve been looking for.
“He’s got a great pedigree and all the attributes to be a success up here, so I’m looking forward to working with him.”
Sporting director Savage added: “It’s always been about quality over quantity for us and we’ve got real quality in Ellis.
“He’s someone we’ve been tracking for a long time and although it looked like he may have gone to the English Championship we’ve managed to attract him up here, which speaks volumes about this club.
“Our thanks go to Everton for their assistance with the move and I am, like I’m sure our fans will be, really excited to watch Ellis play for Hearts.”