Who Plays JJ's Husband on Criminal Minds

On the long-running crime drama Criminal Minds, Jennifer Jareau (played by A. J. Cook) is married to Supervisory Special Agent William LaMontagne Jr., often referred to as JJ’s husband or LaMontagne. The character is primarily portrayed by actor Nicholas Brendon, though it is important to note that Brendon actually played JJ’s husband’s identical twin brother, Kevin, in key story arcs. Other appearances involve guest actors when the plot required alternate timelines or additional family context. Below is a concise guide to how the relationship was depicted and the credited performers.