William West (Sr.) was born in Woodhouse Moor in 1848. He studied and qualified in the fields of pharmacy, and set up a business in Bradford in 1872. He married, and had 3 children, a daughter, and two sons who also became botanists, William West (Jr.) and George Stephen West.
In 1886, William West (Sr.) became lecturer of botany at Bradford Technical College. He became secretary at the Yorkshire Nationalists' Union botanical section, and became president of this in 1899. In 1897, he was elected to the Fellow of the Linnean Society, and played an active role for the British Association.
Between 1878 and 1887, West demonstrated his accurate knowledge of botany, publishing several notes and papers about mosses, lichens, and roses.
His studies did become more specialised, focusing on freshwater algae with his son George. Over the next two years, the two Wests became experts, and eventually published the Monograph of the British Desmidiaceae. Nearing the end of West's working life, he began studying ecology of cryptograms.
He died from heart failure in 1914, associated with problems in the past with asthma.
When citing a botanical name, he is abbreviated as West.