This officer was appointed ensign in the sixty-sixth regiment on the 20th of January 1803, lieutenant in the ninth foot on the 25th of February, and was removed to the first life guards on the 10th of March of the same year. On the 14th of February 1805 he was promoted to the rank of captain in the twenty-eighth regiment, and was removed to the thirteenth light dragoons on the 13th of June following, and in 1809 was appointed deputy assistant quartermaster-general in the army in the Peninsula under Lieut.-General Sir Arthur Wellesley. In March 1810, Captain Whittingham was promoted to the rank of major, serving with the Portuguese army. He was subsequently employed in America; but the chief scene of his services was with the army in Spain, for which he was peculiarly qualified by his perfect knowledge of the Spanish language. He was first permitted to join that service as aide-de-camp to General Castanos, and in that capacity shared in the battle and victory of Baylen. Major Whittingham afterwards served under the Duke of Albuquerque, and was severely wounded at Talavera. Soon afterwards he obtained the command of the Spanish cavalry, and was present at the battle of Barrosa, fought on the 5th of March 1811. On the 30th of May following he was promoted lieut.-colonel in the Portuguese army. He was next intrusted to raise and command a large corps of Spanish troops clothed and paid by the British Government. In 1812, as major-general in command of this well-disciplined corps, he was, in junction with the British army at Alicant, successfully opposed to Marshal Suchet, and was again wounded at the battle of Castalla; after which he served with distinction in command of a division of infantry under Lieut.-General Sir John Murray, and subsequently under Lieut.-General Lord William Bentinck on the eastern coast of Spain. At the restoration of peace in 1814, Lieut.-Colonel Whittingham returned to England, his conduct in Spain being reported in very flattering terms by the British ambassador in Spain and by the Duke of Wellington. On the 4th of June 1814, he was appointed aide-de-camp to His Royal Highness the Prince Regent, with the rank of colonel in the army; and was appointed a Companion of the Order of the Bath, with the honor of knighthood, on the 4th of June 1815. Upon the return of Napoleon from Elba in March 1815, Colonel Sir Samuel Ford Whittingham returned to the Peninsula, at the particular request of the King of Spain, and on his arrival at Madrid, he was invested with the Grand Cross of the Order of San Fernando. In the year 1819 he was appointed governor of Dominica, and in 1822 his services were transferred to India as quartermaster-general of the king’s troops; he subsequently held the command as major-general, to which rank he was promoted on the 27th of May 1825, successively in the Cawnpoor and Meerut divisions.