Phenylketonuria (PKU) is a common inherited metabolic disorder characterised by impaired metabolism of the amino acid phenylalanine. The disease results from a mutation in the phenylalanine hydroxylase (PAH) enzyme, which converts phenylalanine (Phe) into tyrosine (Tyr). The absence or inactivity of this enzyme results in significantly elevated levels of Phe in the blood, which can lead to severe neurological conditions, including intellectual disability, epilepsy, and other developmental disorders. Since its discovery, animal models have played a crucial role for understanding the pathophysiology of PKU, as well as providing recognisable proof of targets and surveying new remedial specialists and in vivo medicines. In the present study, we conducted a comprehensive review of the experimental and non-experimental animal models employed for phenylketonuria and its associated complications.