TMZ reported Wednesday McKellar cited "irreconcilable differences" as the reason she split from the father of her 1-year-old son.
McKellar and Verta married in 2009.
"I am saddened by the end of my marriage to Mike Verta. However, we are committed to raising our son together and we are focused on remaining the best parents we can be," McKellar said in a statement issued to TMZ.
The actress is best known for her work on TV's "The Wonder Years" and "The West Wing."
Verta's film and television credits include "Mega Monster Battle: Ultra Galaxy Legends -- The Movie" and "Inspector Mom."