The former Crystal Palace boss oversaw Saturday's 2-1 loss to Burnley but became the second manager to leave the Hawthorns this term following the sacking of Tony Pulis in November.
First-team coach Moore, meanwhile, wants to see some unity in their near-impossible task of surviving the drop.
Upon taking up his new post, he said: "West Bromwich Albion has always been a family for me. And that's the word I shall focus on - family.
"We need to get the unity back among everyone - the players, the staff, the fans, everyone connected with Albion, because that is the only way forward."
Moore added: "I felt the pain on Saturday just like everyone. It's their club and it's their passion and love for it which makes it so painful at the moment.
"But let's get that unity back. We've had tough days before and we've always bounced back and that's what we will do again."
On Pardew's dismissal, Moore added: "These are never happy days at a club and it's never nice to see people leave their jobs.
"Alan showed faith in me and gave me the chance to work at first-team coach level for which I will always be grateful.
"It's a brutal business at times and unfortunately the results just haven't gone for us.
"But now all I can do is do everything in my power to focus the team for Swansea on Saturday
