Virani steps up after Karren Brady's resignation last week.
He said: “I am proud and honoured to be returning to West Ham United, a Club I have a deep affinity and admiration for.
“This is a massive football club, with incredibly loyal and passionate supporters, a hugely talented and dedicated group of players, coaches and staff, a proud and unique heritage, and an ambition to be as successful as possible, both on and off the pitch.
“I am determined to do everything I can to help the Club achieve our objectives, with the absolute priority and focus of everyone here right now on supporting Nuno Espírito Santo and his players as they look to finish the season positively.
“In recent weeks and months, Nuno, his coaches, the players, staff and our supporters have shown great commitment and collective spirit to help improve our position in the Premier League. We have a mission to achieve between now and the end of the season and nothing will distract us from that.
“West Ham United is a club built on working-class values of hard work, honesty, commitment and togetherness – and those values must continue to be the bedrock of everything we do in the coming weeks and beyond.”
Virani had been with West Ham between 2015-2020 and also had two years as chief commercial officer at Rangers between 2023 and 2025.