William Taylor (1821–1902) was an American Methodist missionary minister, who in 1884 was elected by the Methodist General Conference as bishop over the Methodist missions in Africa for the Methodist Episcopal Church. Taylor spent most of his adult life performing missionary work around the world. He began his missionary service when he was assigned by the Conference to establish missions in California and provide services in San Francisco during the California gold rush of 1849. His other missionary work involved the establishment of self-supporting missions in various countries about the world, bringing him to England, Ireland, India, South America, Australia, New Zealand and Africa, all of which he wrote about in a number of publications. After many years serving as a Methodist missionary Taylor was elected Bishop of Africa. He has received acclaim and is noted for introducing Methodism through his missionary efforts to several countries around the world. Taylor is also credited for introducing the eucalyptus tree to California with seeds he gathered while serving as a missionary in Australia.

Taylor was born May 2, 1821, in the Blue Ridge Mountains of Virginia in Rockbridge County. in the Commonwealth of Virginia. William was the oldest of five sons and six daughters, born to Stuart Taylor and Martha Hickman. In his autobiography, Story of My Life (1896), Taylor describes his grandfather, James, as one of five brothers who were "Scotch-Irish of the Old Covenantor type" who emigrated from County Armagh, Ireland, to the colony of Virginia, about one hundred and thirty years ago" (i.e. 1766). The Hickman family was of English ancestry and settled in Delaware in the late 1750s. Both families "fought for American freedom in the Revolution of 1776", and afterward emancipated their slaves. Taylor’s father, Stuart, was a "tanner and currier—a considered a mechanical genius of his times"; his mother was "mistress of the manufacture of all kinds of cloth". Both parents, he says, were of "powerful constitution of body and mind…their English school education quite equal to the average of their day". Taylor married Isabelle Anne Kimberlin on October 21, 1846 after waiting an mutually agreed upon arrangement that he would serve the church for four years. Taylor had two sons and two daughters, Morgan Stuart, Oceana, William Jr., and Charles Reid. Only Morgan lived to see adulthood.

Before William was ten years old, his grandmother had taught him the Lord's Prayer and explained that he could become a son of God. At age ten he longed for this relationship, but was unsure how to obtain it, during which time he underwent a "profound religious experience", which was affirmed for him in 1841 at the age of twenty. After overhearing the story of a poor Black man who had received salvation, he wondered why he could not, also. He recounts in his autobiography,

So inspired, the young Taylor entered the Baltimore Annual Conference in 1843.

Between 1849 and 1883, Taylor traveled and became involved in many parts of the world as an evangelist missionary. His extensive missionary travels included Australia and South Africa (1863-1866); England, the West Indies, British Guiana, and Ceylon (1866-1870); India (1870-1875); South America (1875-1884); and Liberia, Angola, the Congo, Australia and Mozambique, a global involvement unmatched by no other during his time (1885-1896). Taylor was committed to bringing salvation to those he deemed were in need of it, and to this end he wrote a work, entitled, Reconciliation, or, How to be saved, which he had first published in 1867. To assist other preachers in this effort he also wrote the work, The Best Mode of Preaching the Gospel, published in 1859.

Taylor's missionary career began in San Francisco, California in September 1849, the year after gold was discovered at Sutter's Mill, resulting in the California gold rush. Due to the thousands of people flooding into California the Methodist General Conference deemed it necessary to send missionaries there to provide social work and religious services. The first sent for this undertaking were Reverends William Taylor and Isaac Owen. When Taylor arrived, and with no chapel for people to gather in and listen to sermons, Taylor preached the gospel in the streets to settlers, prospectors, Native Americans, Chinese immigrants, and to the sick and the poor, without receiving any salary. He subsequently came to be known as "California Taylor" throughout his missionary career. In October 1849 Taylor acquired a lot next to the home of Reverend Hatler on Jackson Street who invited him and advanced him the money at no interest to build his own house. Thriving congregations also emerged at Sacramento, San Jose, Stockton, and Santa Cruz while the Gospel was also preached in many of the mining camps. As the immigration increased so did the numbers in the congregations.

Before Taylor was able to set out for California, all the routes to California became flooded with prospectors and adventurers. Not wanting to subject his newly wed and expecting wife to the risks of Indian attack while crossing the plains, or sailing to Panama at the risk of contracting yellow fever by crossing the Isthmus, Taylor got the last berths on the Andalusia, a ship headed for San Francisco by going around Cape Horn at the tip of South America. About one hundred and fifty days into the voyage Taylor's wife gave birth to a daughter on June 8, 1849, who they named Oceana, while they were going around the cape, and who only lived to be about a year old. Their ship, Captain Wilson at the helm, had arrived in the midst of a thick fog and so he cautiously landed just north of the Golden Gate. During the voyage they had experienced incidents of damage to the rigging and sails due to high winds, which the captain was able to remedy en route, without have to stop at any port. Having been informed about the very high cost of food in San Francisco due to the gold rush, the Taylors brought a year's supply of food along with them. As the rents for housing accommodations were also abnormally high, Taylor and his wife found lodging with another Methodist minister who gave them the first month's rent free. Having logging experience, he crossed the bay north to the redwood forests and acquired his own timber in which he used to erect his own house, in less than a month.

Taylor described young San Francisco at this time as a "city of tents". Because of poor living conditions and the scarcity of good food, many took sick with scurvy, tuberculosis or Asiatic cholera, often resulting in death. Here Taylor spent much of his time giving aid and words of encouragement and prayer to those afflicted. The main square had many gambling hotels, where Taylor would spend time outside preaching in the streets about the vices of gambling and drinking, which was, to the amazement of some, often well received by the patrons of those establishments.