Timothy Ha'alilio was born in 1808 on the island of Oahu, he was early on chosen to be the companion of young Kauikeaouli. Both boys were educated under the tutelage of Rev. Hiram Bingham. Upon the death of Liholiho, Kauikeaouli ascended to the Hawaiian throne, taking the name of King Kamehameha III, and Ha'alilio was always close at hand, he served as the king's personal companion, advisor and private secretary for many years. He was also appointed as a member of the Hawaiian Treasury Board along with Gerritt Judd and John Papa I'i.

By 1842, the movement to obtain recognition of Hawaii's independence had entered upon a new and much more promising phase. Sir George Simpson, governor of the Hudson's Bay Company in North America, visited Hawaii in February of that year. Sir George indicated a friendly interest in the government and the people, and acquainted himself with the steps already taken to secure Hawaiian independence. On his recommendation a commissioner would be sent from the islands on this special business with the authority to negotiate treaties with Great Britain, France and the United States. It was decided that Rev. William Richards, a missionary, and Timothy Ha'alilio would be commissioned for this embassy, Sir George Simpson agreed to act with them as a representative of the King of Hawaii. These men were assigned the formidable task of traveling to America and Europe to obtain the formal recognition of the Independence of the Hawaiian Kingdom.

While the commissioners were abroad Lord Paulet attempted to cede Hawaii in February of 1843, this cession was rescinded in July of that year. This news served to redouble the efforts of the commissioners as the very existence of Hawaiian sovereignty was dependent upon their success. The envoys arrived in Washington in 1842 and after several frustrating meetings with Daniel Webster, Ha'alilio and Richards threatened to go to England first. This move obtained them an audience with President John Tyler, who authorized recognition of Hawaii and what was accepted to be United States protection of Hawaii and the American missionaries there against foreign interference. However, it would be another seven years before the United States and the Hawaiian Kingdom would satisfactorily negotiate and sign an official treaty, which was ratified and exchanged on August 24, 1850.

The envoys then traveled to Europe and were successful with their mission and on November 28, 1843, Hawaii received a formal agreement between Great Britain and France recognizing the Independence of Hawaii.

Having accomplished their mission Ha'alilio and Richards finally headed home for Hawaii. However having spent two harsh winters in the United States and Europe greatly affected the health of Ha'alilio. By the fall of 1844 Ha'alilio had taken ill, and spent several weeks in a Massachusetts Hospital. On November 18, 1844, determined to reach Hawaii, Ha'alilio and Richards set sail from Boston on board the ship Montreal. Unfortunately Ha'alilio died on December 3, 1844 and was buried at sea before he could return to his native land.