SPIRULINA platensis (SP) is a nutritional supplement that has a variety of pharmacological properties and it is considered one of the good nutritional supplements for human and animal feed worldwide. Also, exposure to different forms of radiations is almost unavoidable in daily life, especially during radiotherapy. This study aims at evaluating the effect of SP against thyroid dysfunction associated with alteration in liver functions and lipid profile in gamma-irradiated male albino rats. Male rats were divided into four groups 1-Control, 2-Spirulina, rats were given SP via gavages 300mg/kg/day for 15days, 3-Radiation, whole body γ-irradiated rats at a dose of 5Gy, 4-Spirulina+ Radiation, rats were given SP for 15days before irradiation at a dose of 5Gy. The thyroid tissues of the irradiated rats revealed a significant decrease in the activity of the antioxidant enzymes, accompanied by a significant increase in the level of lipid peroxidation end-product malondialdehyde (MDA) indicating radiation-induced oxidative stress. Furthermore, the activity of the apoptotic marker caspase-3 was significantly increased. Also, serum level of thyroid hormones, triiodothyronine (T3) and thyroxine (T4) showed a significant decrease while the thyroid stimulating hormone showed an increase. Thyroid dysfunction was accompanied by alteration in liver function enzymes and a state of hyperlipidaemia, SP treatment has significantly decreased oxidative stress and caspase-3 activity in thyroid tissues, which was accompanied by a significant improvement in the level of thyroid hormones, liver functions and lipid profile. SP may be a useful adjunct to attenuate thyroid disorders associated with liver dysfunction and dyslipidaemia in irradiated rats by its free radical scavenging and potent antioxidant activity.