Thyrotoxic periodic paralysis (TPP) is a rare, potentially life-threatening complication of hyperthyroidism characterized by recurrent muscle weakness and hypokalaemia. We report a case of a 33-year-old male presenting to the emergency department with sudden generalized weakness following prolonged sitting, preceded by nonbilious vomiting. A similar self-limiting episode occurred one month prior. The patient, a fruit picker with no significant medical history, exhibited blood pressure of 143/77 mmHg, heart rate of 69 bpm, and respiratory rate of 26 breaths/min. Neurological examination revealed bilateral lower limb power of 2/5, absent deep tendon reflexes, and upper limb power of 3/5. No overt hyperthyroid signs were noted. Biochemistry showed severe hypokalaemia (potassium 1.7 mmol/L) and overt hyperthyroidism (TSH <0.01 mU/L, free T4 27.73 pmol/L). ECG displayed prolonged PR interval and U waves, consistent with hypokalaemia. TSH receptor antibodies and a thyroid uptake scan confirmed Graves’ disease. Intravenous potassium chloride (60 mmol) normalized serum potassium within 6 hours, with clinical improvement. The patient was started on carbimazole (10 mg TDS) and propranolol (10 mg BD) and monitored in the ICU. Discharged after three days, he remains asymptomatic with improving thyroid function on a weaning dose of carbimazole. TPP, more common in males and East Asian populations, results from thyroid hormone-induced sodium-potassium ATPase hyperactivity, driving potassium into cells. Treatment involves cautious potassium replacement, beta-blockers, and definitive hyperthyroidism management. This case underscores the importance of considering TPP in young males with sudden weakness and hypokalaemia, emphasizing multidisciplinary management to prevent complications like arrhythmias. Awareness of TPP is critical, particularly in non-Asian populations where it may be underdiagnosed.