Jeremiah was born in an Anglo-Indian Roman Catholic family in Arakkonam, Tamil Nadu. Her father is a lawyer at the High Court in Chennai. She has one younger sister who lives and works at Leuven, Belgium as a research assistant. She was raised near Chennai and went to Sacred Heart Matriculation Higher Secondary School and graduated from Women's Christian College. She said that she was quite a geek and wanted to be a psychiatrist until she completed her 12th board exams. Jeremiah learnt classical piano when she was age of eight. At the age of 10, Andrea was a part of a Jackson Five-style troupe called Young Stars which formed the base of her early singing and music composing career. She was also a theatre artist in her college and appeared in several stage plays organised by The Madras Players and EVAM. She also organised a company The Show Must Go On (TSMGO Productions) to promote live art and artistes. Andrea said that as a college student, she had turned down every film offer she got as she had no intention of becoming a film actor.
She was moreover widely known as a notable singer and has sung popular Tamil songs composed by Harris Jayaraj (such as Kannum Kannum Nokia from Anniyan and Karka Karka in Vettaiyaadu Vilaiyaadu) and Yuvan Shankar Raja (such as Oh Baby from Yaaradi Nee Mohini and the most recent Adada Vaa from Sarvam along legendary composer 'Maestro' Ilaiyaraaja. Reportedly, she has sung several songs in the upcoming Aayirathil Oruvan, in which she acts as well. Apart from singing under other composers' direction, Andrea Jeremiah also produces her own music. She composed, wrote and sung a single, titled "Soul of Taramani", as a promo for her Tamil romantic-drama Taramani. She has composed several music themes, songs and albums.