He has previously captained Worcestershire and Birmingham Phoenix in short-form cricket, and has led England in one ODI and 11 T20Is.
"I'm really grateful to be given the opportunity to captain my hometown club," Moeen said. "I grew up just a short walk from Edgbaston, always dreamed of playing at this great stadium when I was a child, and now to be made captain is something special.
"I've had several proud moments in my cricket career but becoming Bears captain having returned to Edgbaston after 16 years is without doubt one of highlights."
Moeen will miss the start of the Blast season while playing for Chennai Super Kings in the IPL, and Alex Davies will deputise for him after his appointment as Warwickshire's vice-captain across formats.
Warwickshire, playing under their Birmingham Bears moniker, were eliminated in the Blast's quarter-finals last year and have brought in Glenn Maxwell and Hasan Ali as overseas signings in their bid to reach Finals Day in 2023.
"The squad looks incredible," Moeen said. "There's talent right through the line-up from top to bottom. But what I'm really encouraged about is that there are some young players who, like me, came up through the pathway and academy system at Edgbaston."
Mark Robinson, Warwickshire's coach, said: "Moeen is not only an extremely talented cricketer, but a leader on and off the pitch. Anyone who has spent time with Mo talks positively about his ability to motivate a team, whilst staying calm in the most pressurised moments.
"Mo has led teams in many franchise leagues around the world and I know how excited he is to be a Bear and lead us at Edgbaston. We're all excited to see him and we're really looking forward to welcoming him into the changing room."