Joseph Edward Knowles was born in Kendall, Montana, on June 15, 1907. He grew up in San Diego, California. At age twenty, two years before the beginning of the Great Depression, he moved north to another town on the coast of California---Santa Barbara. There he began studying fine art at the School of Arts (1927-1930), under the supervision of Frank Morley Fletcher, previously director of the Edinburgh College of Art. Fletcher, who was trained in portraiture, landscape painting, and woodblock printing, was a great influence on young Knowles. It was there that Knowles learned the art of color woodblock printmaking, a medium in which he showed great skill.

Not long after completing his studies with Fletcher, Knowles began teaching art. For a period of thirty years, from 1930 to1960, he taught at the Cate School in Carpinteria, California. In 1934-1935 Knowles traveled throughout Europe, further developing his artistic skills in England, France, and Italy. Upon his return, he continued to teach art at various schools and institutions: Cate School, Crane Country School, extension classes at the University of California at Santa Barbara (UCSB), and at the Santa Barbara Museum of Art (SBMA). Knowles also served as an art education consultant for the County of Santa Barbara. In addition, he was founding co-director and president of the Santa Barbara Fine Arts Institute (1969-1972), which later developed a specialization in photography and became the Brooks Institute of Photography.

Knowles died at his home in Santa Barbara on September 8, 1980.

Much of Knowles' watercolor work is associated with what has been termed the "California School," a loose grouping of artists throughout the state that included such figures as Millard Sheets, Phil Dike, Dong Kingman, George Post, and the Santa Barbara painters Dan Lutz and Standish Backus, Jr. The California School artists, including Knowles, were known for their fresh, direct, spontaneous style of watercolor painting. Knowles and other members of the school found inspiration in nature and the built environment alike, emphasizing elements of design in their exuberant, boldly stated, colorful scenes from everyday life. While painting in a representational manner, Knowles generally avoided photographic realism, preferring subjective interpretation of his subjects. In this, as well as in his experimental approach and vigorous brushwork, he displayed a strongly modern sensibility. Knowles often used the wet-on-wet watercolor technique as he painted seascapes and landscapes, mostly along the California coast. He also employed dry-brush techniques in many of his paintings, often leaving some of the white of the watercolor paper exposed. Some of the latter depict trees and other forms in a broken and airy manner that recalls Cezanne. Knowles' colored woodblock prints are more reserved and exact in their draftsmanship than his paintings. Spare, clean, lyrical lines are drawn to illustrate floral motifs and boat scenes with a touch of asymmetry conjuring Japanese woodblock prints. His murals from the post-World War II period are considerably more modern in their approach and show an emphasis on design and color.

Bio by Holly Gruendyke