Laia Costa (Catalan: [ˈlajə ˈkɔstə]; born February 18, 1985) is a Spanish actress from Catalonia. She earned a degree in advertising, public relations and marketing, as well as a PhD in political science and media studies, before beginning her acting career at the age of 26. She is best known for starring in the critically acclaimed one-shot German thriller Victoria (2015), for which she received several accolades, including a German Film Award for Best Actress, becoming the first foreign actress to win a Lola and a BAFTA Rising Star Award nomination. After initial minor television roles in Spain, including an appearance in Polseres vermelles (2013), she went on to star in the romantic dramas Newness (2017) and Only You (2018), the horror thriller Piercing (2018), the romantic comedy Duck Butter (2018), and the multi-narrative drama Life Itself (2018).

Costa featured in the romance series Foodie Love (2019), the financial drama Devils (2020), and the science fiction anthology Soulmates (2020). She gained widespread acclaim in Spain for her portrayal of Amaia in Lullaby (2022), becoming the most acclaimed performance of the awards season, winning the Goya Award for Best Actress, along with a Feroz Award, a Forqué Award, and a Platino Award. She later starred in the rural drama Un amor (2023), earning her a second Platino Award, and portrayed Moghedien in the Amazon Prime Video high fantasy series The Wheel of Time (2023–2025). She starred in the supernatural horror Lee Cronin's The Mummy (2026).