Lizzy was born to father, Richard Caplan, a lawyer and mother, Barbara, a political aide. She is the youngest of three children, Benjamin, her brother and Julie, her sister. When Lizzy was just 13-year-old, her mother died of illness.
She attended Alexander Hamilton High School. As she was also interested in music, she joined the school’s academy of music. She loved to play piano in the beginning but later she decided to pursue a career in acting.
She also loved playing soccer when she was in school. Lizzy graduated from her high school in 2000 but she didn’t continue her studies as she wanted to focus just on acting. She started her official acting career from 1999. Her debut role was in the series Freaks and Geeks as Sara. She gave a guest appearance on numerous shows. She has also been in one of Jason Marz’s music video You and I Both.
Due to her exceptional skills in acting, she was one of the most demanded personality in TV series. She became much famous when she played Janis Ian in Mean Girls in 2004. In 2006, she played Sara Weller in Love is the Drug and was named one of 10 actors to watch by Variety.
In 2008, she was nominated for a Saturn Award for best-supporting actress for her role as Marlena Diamond in Cloverfield. Her role in Masters of Sex continued from 2013 to 2016, which was one of the famous show she’s done so far.
In 2006, she started dating a famous American actor Matthew Perry, who is widely known as Chandler Bing from F.R.I.E.N.D.S. The couple dated for six years and got separated in 2012. After three years, in 2015, she had an encounter with a British Actor, Tom Riley.
He was born in Maidstone, Kent, England, United Kingdom and is famous for 'I Want Candy' (2007). After a year of getting together, the couple got engaged. After a year of engagement, the couple married on 2nd September 2017.
Lizzy lives in the Hollywood Hills and has an expensive cat, Lisa Turtle. As she has worked on many movies as well as TV shows, she has earned a lot of wealth from her work. She appeared on 45 episodes of one of her famous TV series, Master of Sex. From the series, she earned over $100,000 each episode. With such earnings, her estimated net worth as of 2017 is $4 million.