Agnes Baldwin Alexander (1875–1971) was an American author and a member of the Bahá'í Faith.
Agnes Baldwin Alexander was born July 21, 1875, in the Kingdom of Hawaii. She was the youngest of five children born to William De Witt Alexander and Abigail Charlotte née Baldwin Alexander. The Alexanders were a scion of two of Hawaii’s most illustrious Christian missionary families—the Alexanders and the Baldwins. Her father was one of Hawaii’s most famous men as President of Oahu College, author of "A Brief History of the Hawaiian People," and first Surveyor-General of the Hawaiian Islands.
Alexander graduated from Oahu College in 1875, later doing undergraduate work at Oberlin College and U.C. Berkeley. After teaching for a few years, she fell prey to chronic illness. In 1900, she joined a group of Islanders who were going on a tour of Europe. In November 1900, She was in Rome where she encountered an American Bahá’í woman and her two daughters who were returning from a Bahá’í pilgrimage in the Holy Land, then called Syria. As the result of an epiphany one night, which she described as “neither a dream nor vision”, she embraced the Bahá’í Revelation and accepted its new Manifestation, Bahá’u’lláh, whose name means ‘The Glory of God’.
At the request of Bahá’u’lláh’s eldest son, ‘Abdu’l-Baha, Miss Alexander pioneered the Bahá’í Faith in Japan in 1914. In 1921 she became the first to introduce the New Gospel in Korea. Except for extended vacations in Hawaii, Agnes spent over thirty years in Japan.
Alexander became an early advocate of Esperanto and used that new international language to spread the Bahá’í teachings at meetings and conferences.
At the request of Bahá’u’lláh’s great-grandson, Agnes Alexander wrote two histories: "Forty Years of the Bahá’í Cause in Hawaii: 1902-1942" and "History of the Bahá’í Faith in Japan: 1914-1938". Both of these volumes were published posthumously.