Teo Oi Mei graduated with a Bachelor of Science (majoring in Mathematics) from the National University of Singapore and obtained her Postgraduate Diploma in Education from the National Institute of Education (NIE), Singapore. In 2005, Oi Mei received her Postgraduate Diploma in Departmental Management from NIE. Passionate in the Teaching and Learning of Mathematics, she obtained her Master of Education (Mathematics Education) from NIE in 2006.

Oi Mei taught Mathematics at St. Andrew’s Junior College from 1997 to 2008 where she held the appointment of Head of Department for Mathematics since 2002. In 2008, she was awarded the National Day Honours (Efficiency Medal).

Subsequently, Oi Mei joined the Mathematics Unit in Curriculum Planning and Development Division at the Ministry of Education for three years before heading the Mathematics Department of Jurong Secondary School for another three years. She has also undergone International Baccalaureate's specialised training in teaching Mathematics and in guiding students for their Creativity, Activity, Service projects.

When Oi Mei was a student, she joined the band as a flutist. She also served as the teacher-in-charge in St Andrew’s Junior College Concert Band for a few years and brought the band to participate in an overseas competition in Hawaii. Having a keen interest in Music, she hopes to contribute as a Mathematics teacher to bring out the best in every SOTA student, both in Arts and Mathematics.