Singer was born in London in 1846 to a Hungarian father and English mother. At age 8 (1855) his mother took him to visit Raab, then in Hungary. She believed he would get a better education there, but shortly after their arrival she contracted cholera and died within 24 hours. Simeon remained there a few months with family members, and then returned to London. He "possessed an exceptional mind", and at the age of 13 he was the recipient of the Barnett Myers Scholarship, allowing him to study.