Othmar Schmalz was born in the schoolhouse of Neu St. Johann (today part of Nesslau-Krummenau) where his father worked as teacher. He was the oldest of three children and spent his first years in Bazenheid. His family later moved to St. Gallen where he attended school and later started his education to become a dental technician. In Munich he attended the school for dentists, graduating with honors, before returning to St. Gallen and working as assistant. In 1929 Schmalz started his own dental office in Niederteufen. After his retirement from active water polo he became a board member of his home club SC St. Gallen. He was also president of the district residents association in Niederteufen, established a kindergarden, and sang in the male choir. Schmalz died after a short illness and was survived by his wife and their three daughters.