In junior high school, Megan was on the same cheerleading squad as Lana Lang and Julia Altman. Julia was tragically hit by a car and remained on life support for several years.
When Julia's father, Joseph Altman finally took her off life support and she died, he decided to commit suicide, but was prevented by Jordan and Clark. Megan went to visit him in the hospital and expressed regret at what happened to Julia, saying they had fought the night she was hit and she blamed herself for letting her walk alone.
Upon his recovery, Coach Altman decided to extract revenge on Megan. Jordan tried to warn her but she was upset and scared. Altman abducted Megan, then Lana, and prepared to burn them alive in his basement. However, Jordan was able to recall enough details of Megan and Lana's shared deaths to direct Clark to the house, and the two of them saved both girls.
- It is unknown if Megan Calder was among the hundreds of students, shown graduating from Smallville High, in the spring of 2005.