Entertainment Weekly previously reported that Clark, who won her Tony for her performance in The Light in the Piazza, will play a "pivotal role" in the acclaimed series.

The singing actress has been cast as Ellen, the mother of Carrie Mathison, who is played by Emmy winner Claire Danes.

Clark will be seen in the season finale, which airs at 9 PM ET and is titled "Long Time Coming." In the broadcast, "Carrie and Saul investigate what she saw in Islamabad," according to press notes.

"CIA officer Carrie Mathison (Claire Danes) is tops in her field despite being bipolar, which makes her volatile and unpredictable. With the help of her long-time mentor Saul Berenson (Mandy Patinkin), Carrie fearlessly risks everything, including her personal well-being and even sanity, at every turn," according to production notes for the series. "You won't be able to turn away from this gripping, emotional thriller in which nothing short of the fate of our nation is at stake."

Clark was last seen on Broadway in the Main Stem debut of Rodgers and Hammerstein's Cinderella.