Ietada was born as the first son of Koretada MATSUDAIRA, the third head of the Fukozu Matsudaira family, and the daughter of Nagamochi UDONO at Fukozu-jo Castle, the castle of the Fukozu Matsudaira family, in Nukata district, Mikawa Province (present day Fukozu, Koda-cho, Aichi Prefecture).
深溝松平家第3代当主松平伊忠と鵜殿長持の娘の長男として、深溝松平家の居城である三河国額田郡の深溝城（現在の愛知県幸田町深溝）で生まれた。