<Li> Carrie Preston as Mandy Newhouse, twin sister of Samantha and one of Kimmy's bridesmaids . </Li> <Li> Susan Sullivan as Isabelle Wallace, wife of Walter, mother of Kimmy, and future mother - in - law of Michael . </Li> <Li> Christopher Masterson as Scotty O'Neal, youngest son of Joe and younger brother of Michael and future brother - in - law of Kimmy . He serves as his brother's best man at his wedding . </Li> <P> The film opened at No. 2 at the North American box office, making $21,678,377 USD in its opening weekend, behind Batman & Robin . It stayed in the top 10 weekly U.S. box - office for six consecutive weeks, and eventually earned $127,120,029 . The worldwide gross total stands at $299,288,605 (listed as one of the 10 biggest films of 1997 both domestically and worldwide). </P>

Who played scotty in my best friend's wedding