Peter Klaven is a fictional character from the 2009 romantic comedy film, I Love You, Man. He is portrayed by actor Paul Rudd and is a successful real estate agent who struggles to find male friends as he prepares for his upcoming wedding. Throughout the film, Peter embarks on a quest to make new male friendships, leading to humorous and awkward situations. His journey highlights themes of friendship, love, and the importance of male bonding, ultimately culminating in a deeper understanding of his relationships with both friends and his fiancée, Zooey, played by Rashida Jones.