Caroline Quentin (Men Behaving Badly) and James Fleet (The Vicar Of Dibley) are also among the cast.
Harrison will play Ben Turnbull, a university graduate who reluctantly returns to his home town after three years away and reunites with old friends Beth (Rebecca Humphries), Eggman (Seann Walsh) and Oakley (David Fynn).
"It's very exciting to be working with such a brilliant cast on a new project," said Andrew Newman of Objective Productions.
"Comedy Central already have many of the best comedy shows from around the world and we are very proud to be making a new British one for them."
Sarah Farrell of Comedy Central added: "It's with huge excitement that we're able to reveal the fabulous cast that this script and Objective have attracted. We can't wait to see the finished programme and have very high hopes that this is our next big show."
Big Bad World has been written by Joe Tucker and Lloyd Woolf, with additional episodes penned by Kevin Cecil and Andy Riley (Black Books). Tristram Shapeero (Peep Show, Community) will direct.
