Claire Boucher was born and raised in Vancouver, British Columbia. She graduated from Lord Byng Secondary School and moved to Montreal, Quebec to attend Montreal's McGill University. It was during her studies that she began to record and perform under the name Grimes. However, as Grimes became a more serious endeavor for her, she began to miss a large number of classes at McGill, and only showed up for classes when she had to take exams; resulting in the university taking punitive actions against her and she was expelled.
In 2009, Boucher and her then-boyfriend from Tennessee constructed a 20-foot houseboat, named the "Velvet Glove Cast in Iron," with the intention to sail it down the Mississippi River from Minneapolis to New Orleans. The cargo included chickens, a typewriter, 20 pounds of potatoes and a gifted copy of Mark Twain's The Adventures of Huckleberry Finn. Boucher and her companion adopted the names "Varuschka" and "Zelda Xox" for the trip. Due to engine trouble and subsequent harassment from the Minnesota police, the journey was cut short and the houseboat and chickens were impounded.