As the son of General Sir Frederick Wetherall, George Augustus Wetherall was educated in the senior department of the Royal Military College, and entered the army in 1803. He served as brigade-major at the Cape of Good Hope in 1807, took part in the conquest of Java as aide-de-camp to his father, from 1822 till 1825 was military secretary to the commander-in-chief of Madras, and in 1826 was appointed deputy judge-advocate-general in India.