Happy birthday,  Mariska Hargitay! The Law & Order: SVU star turns 55 on January 23, 2019.

Now in its 20th season, SVU has tied with both Gunsmoke and the original Law & Order series as

the longest-running scripted non-animated primetime TV series in the U.S. Cast members have come and

gone over the years, but Hargitay has played the heart and soul of the show,  Olivia Benson, since day one.

Hargitay often takes to Instagram to share fun, behind-the-scenes photos of her fellow cast-members.

Fans went nuts when she recently shared this reunion photo with  Christopher Meloni, who played her partner, Elliot Stabler, from season 1 to 12.