The mutual says the Lifetime ISA is a "natural fit with their family-focused offer", which includes lifetime mortgages, adult and junior investment ISAs and life assurance products.
OneFamily says further information about its plans will be available soon.
Last month, OneFamily launched two lifetime mortgage products which allow consumers to choose how much interest they want to pay and for how long on either a fixed or a variable interest rate.
The additions bring its lifetime mortgage range to six products.