Stephanie J. Block is an American actress and singer who has earned widespread acclaim for her powerful voice and commanding stage presence, establishing herself as one of the most respected performers in Broadway theatre. Born Stephanie Janette Block on September 19, 1972, in Brea, California, she built a career defined by originating roles, breathing life into iconic characters, and delivering performances that have earned her the industry's highest honors.

Block made her Broadway debut in 2003, originating the role of Liza Minnelli in The Boy from Oz. Her association with the blockbuster musical Wicked began during its early development stages in 2000, when she read for the role of Elphaba. Although she was not cast in the original Broadway production, she became the first actress to play the role in the show's first U.S. national tour in 2005, and she later reprised the part on Broadway from 2007 to 2008. These performances cemented her reputation as a leading lady of the modern musical stage.

A three-time Tony Award nominee and six-time Drama Desk Award nominee, Block reached the pinnacle of her career in 2019 when she won the Tony Award for Best Actress in a Musical and the Drama Desk Award for Outstanding Actress in a Musical for her lead performance in The Cher Show. Because of the COVID-19 Broadway shutdown, she held onto the title of Best Actress for over two years. She also received Tony and Drama Desk nominations for her performances in The Mystery of Edwin Drood in 2013 and Falsettos in 2016. Additional Drama Desk nominations came for her work in the Off-Broadway productions of By the Way, Meet Vera Stark in 2011 and Little Miss Sunshine in 2013, as well as for the Broadway production of 9 to 5 in 2009.

Beyond the stage, Block has appeared on numerous cast recordings and released a solo album, This Place I Know, in 2009. Her television credits include recurring roles on Madam Secretary in 2017 and Rise in 2018. She starred as The Baker's Wife in a Broadway revival of Stephen Sondheim's Into the Woods, a role she later reprised in the U.S. national tour. In 2024, she made her London stage debut starring in a Barbican Theatre revival of Kiss Me, Kate.

Block is married to fellow actor Sebastian Arcelus, with whom she shares a family. With her remarkable range, dedication to her craft, and a career spanning originating roles, national tours, and award-winning Broadway performances, Stephanie J. Block remains a defining presence in American musical theatre.