Shahi has filed for divorce to end the pair's 11-year marriage, according to documents obtained by Us Weekly.
The 40-year-old filed papers in Los Angeles on 4 May (20), citing irreconcilable differences. She listed the date of separation as 14 April.
The couple met when she guest-starred in an episode of his former series "Reba" in 2004 and Howey and Shahi wed in Las Vegas in 2009.
They are parents to son William, 10, and five-year-old twins Violet and Knox.