Ellamay Mantie is currently a grade twelve student at Sir Oliver Mowat Collegiate in Toronto. She began playing the cello at the age of five, under the guidance of Daphne Grittani. Since then, her teachers have included Ben Peterson, Thomas Landschoot, Jenna Dalbey, and currently, Joowon Kim. She has played in masterclasses for performers and teachers such as Alisa Weilerstein, Joseph Johnson, Sheku Kanneh-Mason, David Hetherington, and Alan Harris. In 2020, she received the Kiwanis Club of Casa Lima Voltr Ivonoffski Memorial Award, and was awarded a similar scholarship the previous year. More recently, she was selected as an alternate for the 2020 season of the National Youth Orchestra of Canada.

In the summer of 2019, Ellamay attended the Eastman Cello Institute in Rochester, working with Alan Harris, Kathleen Kemp, Daniel Ketter, and Cora Swenson Lee. She was a member of the Toronto Symphony Youth Orchestra for the 2018/19 and 2019/20 seasons; in 2017/18 she was a member of the Phoenix Youth Symphony. She has played under conductors such as Simon Rivard, Sir Andrew Davis, and Tito Muñoz. In addition to orchestral playing, Ellamay has also been involved with multiple chamber ensembles. She was a founding member of the Willow String Quartet, an ensemble specializing in folk and traditional fiddle music. She will attend the Schulich School of Music for cello performance at McGill University in Fall 2021.