Jimmy Olsen was played by Michael Landes in season one; he was let go at the end of the first season due to producers thinking he looked too much like Dean Cain. Justin Whalin was brought in for season two, and he continued the role until the series ended.
In the first season, Michael Landes played Jimmy Olsen but was let go due to his resemblance to Dean Cain. For the second season, Justin Whalin took on the role, continuing it until the show ended.