The 24-year-old forward penned a deal with the newly-promoted Premier League side after arriving from Turkish Super Lig club Kasimpasa.
Aware the Claret and Blue Army were interested in securing his signature, Trezeguet asked his countryman Elmohamady, who has been with Villa since 2017, questions concerning the club and the right-back was at hand to convince him on the move.
"Ahmed is a good friend of mine. He's like my brother, who I've played in the national team with for five years,” Trezeguet told the club website.
"He's my captain and always speaks with me about Aston Villa, saying it's an amazing club and that I'd be happy here.
"I asked him a lot of questions. He will help me and believes I will help the team. It will help having him here with me and I look forward to working with him again.”
"As for joining, I'm happy to be here at one of the biggest clubs around. I hope I can help the team to be successful – I will do my best,” he added.
"I'm looking forward to playing in the Premier League – it's a dream."
Trezeguet, who has 41 appearances for Egypt, was part of the Pharaohs’ squad that was eliminated in the Round of 16 of the 2019 Africa Cup of Nations.
The forward could make his debut for Aston Villa when they take on Charlton Athletic in a pre-season friendly game on Saturday.