Lexa is a fictional character from the American post-apocalyptic science fiction television series The 100 on The CW. A recurring character, she does not appear in the books on which the series is based, and is portrayed by Alycia Debnam-Carey. The commander of the allied Grounder clans, Lexa is proven to be a reasonable leader and strong warrior. She considers love a weakness, a view significantly impacted by the death of her girlfriend, Costia. Though she starts to show romantic feelings for Clarke Griffin (leader of the Sky People), and takes Clarke's views into consideration, she puts her people first, including at the expense of losing Clarke's trust.