Kingsley (King) Dawson Brock was born in Pasadena, California on 3 February 1912 to William W. and Rhoda Ann Dawson Brock. He attended the Grover Cleveland Elementary School, the John Muir Technical High School, the Pasadena Junior College, and the Stickney Art School. While a student at the Pasadena J.C., Brock was a member of the architectural club, T Square, and he graduated in 1933. In May 1935, a solo exhibition at the Pasadena Junior College featured his charcoal drawings, and landscape, figure, and still life paintings. The related newspaper clipping in the Pasadena Public Library stated, “Variety and novelty of technique mark the exhibition.” Following his studies, Brock focused on creating posters and layout work, showing particular aptitude in black and white drawings. According to an undated newspaper clipping in the Pasadena Public Library, an exhibition of his drawings was mounted in Dabney Hall at the California Institute of Technology in Pasadena.

Brock found employment on the WPA Federal Art project in Southern California and became a teacher in the program. When Brock registered for the draft on 16 October 1940, he was working for the Baruch Corporation, one of the largest general contractors in Southern California. Later Brock worked as an illustrator for the Fort MacArthur Newspaper in San Pedro, California during WWII. He enlisted in February 1945 and, upon his return to civilian life, he worked as a carpenter to support his family but continued creating art.

During the years 1952-1958 and 1967, King Brock was a featured artist in the Women’s Sunday Morning Breakfast Club’s Cinderella International Souvenir Book. The WSMBC, an organization founded by Theresa Lindsay, sought to help the poor, educate the youth, honor the aged, and contribute to the agencies that helped the disenfranchised. Many of Brock’s drawings were seen as a result of the WSMBC’s support, and a series of paintings entitled the New Breed received critical acclaim after gracing the cover of the group’s annual commemorative book.

A member of the Pasadena Society of Artists for more than forty-five years, King Brock’s work was featured in Ebony and Jet magazines and he was involved with the Brockman Gallery in Los Angeles’ Leimert Park neighborhood, which was the first major gallery run by and for Black artists

In recounting a highlight of his career, King Brock referred to his portrait of Martin Luther King Jr., commissioned by Dr. Leroy Weekes and Dr. H.C. Hudson, titled His Dream. He felt that it captured the essence of Dr. King’s message to African Americans. The painting featured a picture of the slain civil rights leader in the foreground and a number of faces in the background, which were symbols of a new generation that, according to King Brock, he included in the painting to express his hope for a society that was open to freedom of creative expression without the infringement of racism and injustice. According to the February 2019 Los Angeles African American Culture and Entertainment Guide, “Brock was one of the first African American artists to have his work exhibited at the Los Angeles County Museum of Art. His realistic charcoal depiction of Reverend Martin Luther King Jr. in deep contemplation was recently on display in the Los Angeles office of Senator Kamala Harris.”

During Richard Candida Smith’s January 1990 interview with John W. Outterbridge at Watts Tower, Outterbridge recalled Kingsley Brock: "There was a man in Pasadena who's still living. I see him walking about every now and then. I don't think he's doing art anymore. His name was King Brock. “King Brock,” that’s what we used to call him. We used to take King Brock and the man that you are talking about- They were just kind of giants from the past that really were not giants that everybody knew about. They weren't as well-known as you thought they should have been. Because Brock was a man who thought too fast, and he spoke just like he thought. Just like his thoughts came, he spoke, very rapidly, you know. He used to come to affairs in the parks, outdoor exhibits, with a big roll of white paper—a roll about two feet wide, the kind of thing that you could just pull out and make sketches on. Whatever he saw, whatever the conversation was about, whatever ideas he had flowing through his mind, that’s what he’d just sketch out in charcoal. People would become fascinated with those sketches. He’d simply tear it off and let them have it. Whatever they’d give him for it, he’d take that, then roll it out again. He’d just keep sketching and sketching and sketching."

Kingsley Dawson Brock died in Pasadena, California on June 29, 1995.