The 'Criminal Minds' star's representative confirmed the news in a statement, reported E! Online.
"Jennifer and Brian are thrilled to be expecting their second child later this year," the representative said.
Hewitt, 35, began dating her 'The Client List' co-star in 2012. They married on November 21, 2013, and five days later their first child, daughter Autumn James Hallisay, was born.