Re Colin  FamCA 449 was a pseudonym decision in late April 2014 of the Family Court of Australia, regarding phase 2 treatment for gender dysphoria, on the application of the parents.
Born as female (see ), the child was said to have identified and behaved as male from as early as age 9 months: .
When aged 13 years, the Court authorised reversible hormone treatment to suppress puberty:  – . The proposed phase 2 treatment would entail hormone treatment to stimulate physical changes which bring about the characteristics of the affirmed sexual identity which would not be readily reversible.
The court noted that in an earlier decision Re Jamie  FLC 93-547 the Full Court of the Family Court dealt comprehensively with the circumstances in which court authorisation is necessary for Phase 1 and Phase 2 treatment: .
Each of Colin’s psychiatrist, paediatric endocrinologist and counsellor had expressed the opinion that he was Gillick competent: . The court made findings accordingly () and consistent with the earlier decision of the Full Court, being satisfied that a child is Gillick competent and in the absence of any controversy, the child could consent to the treatment and no court authorisation was required.