Laine Mägi (born Laine Michelson-Adamson; February 3, 1959) is an Estonian stage, film and television actress, dancer and choreographer and dance pedagogue who began her career as a teenager. She is the founder of the Laine Mägi School of Dance, based in Pärnu.

Laine Michelson-Adamson was born in Kehra to Peeter and Elli-Anniki Michelson-Adamson (née Pennie). She has one brother who is two years younger. Her first cousin is actress Terje Pennie-Kolberg. She became interested in ballet at an early age and began taking lessons at the Tallinn Ballet School at age nine, taking the train from Kehra to Tallinn. She made her debut at the Estonia Theatre at the age of ten in a stage production of Astrid Lindgren's Pippi Longstocking. She later had to abandon ballet classes in 1973 due to poor health. From 1976 until 1981, she performed as a dancer in various venues throughout Tallinn.

She attended secondary school in Tallinn, graduating in 1977, then enrolling in the Tallinn State Conservatory (now, the Estonian Academy of Music and Theatre) to study acting under instruction of Aarne Üksküla, graduating in 1982. Among her graduating classmates were Margus Oopkaup, Jaan Rekkor, Anu Lamp, Sulev Teppart, Andrus Vaarik, and Viire Valdma.