Born in Lincoln, Nebraska, Willana Ruth Gilliam was raised in Minneapolis. Her father worked as a waiter on the railroads, but died when she was 13. She briefly attended the University of Minnesota, but left school to work as a domestic in Chicago, helping support her aging mother during the Depression. She married William Waddy in the 1930s, but the couple was later divorced.  They had one daughter.  In Chicago, Waddy met Margaret Burroughs at the Southside Community Art Center  (founded by Margaret Burroughs in 1940).

"When I went to Chicago, I saw so many black people, more than I had ever seen in my life. I fell in love with it just as soon as I got off the train. I mean, I saw people just walking up and down. I said, "This must be heaven!" I said, "I'll never, ever leave Chicago, as long as I live." I just fell in love with it. They had more black people in Chicago in one block than there were in the whole city of Minneapolis.”

Waddy applied for a job as a blueprint reader and solderer at Lockheed, but was denied because of her race.  That turn of events led her to move with her daughter to Los Angeles in 1942, becoming a riveter at the Douglas Aircraft Corporation after the war, and also working as an intake clerk at LA County Hospital (ironically, one of her co-workers there was Noah Purifoy) , and for the USPS as a mail carrier.  She even opened her own business for a brief time—a hotdog stand.  While working at the hospital, she was diagnosed with epilepsy and was forced into early retirement.

Waddy had a very strong work ethic and also believed creating “good art” was work. “ 'I guess you'll have to have state aid.’  So since I was fired, I got state aid. I didn't have to make any application because it was from county to county, you know, from one government agent to another government agent. So it was no problem at all. They just sent me the check. But I was very, very angry...I wanted to work. I was in the habit of working .”

One positive result of her not working was that she now had the time to return to her interest in art.  She completed the Famous Artists’ Home Study Course in 1962.  This was a correspondence course, founded in 1947 by significant artists such as Norman Rockwell.  The students were instructed in technique and media, and received direct feedback from the faculty.  Already an organizer and activist, one of Waddy’s ambitions was to organize juried exhibits for Black artists, including a proposed exhibit at the Los Angeles County Museum of Art.  She was aware of exhibitions being organized in other cities to celebrate the centenary of emancipation.  Also in 1962, Waddy founded the Art West Associated, centered in Los Angeles, with a northern chapter in San Francisco, organized by Waddy’s friend, Evangeline Montgomery. The association’s agenda was to organize juried exhibits and sell prints by Black artists, advertising in magazines like Essence.  This project was supported by the National Endowment for the Arts.

Waddy reached out to Victor Roelof-Lanner, the General Director of the Cultural Exchange Center, about including works by Black artists in the annual exhibition (since 1954), Prints by California Artists, and showed him a portfolio of prints created by Margaret Burroughs for a Chicago celebration of the centenary of emancipation.   Roelof-Lanner suggested to her that she go further and create a portfolio of only work by Black artists, which resulted in Prints by American Negro Artists (1965).  Waddy traveled by bus around the country searching for the work of Black printmakers.  She had seen an advertisement from Greyhound offering a $100 round-trip ticket to anywhere they regularly went, so she asked Roelof-Lanner for the money.  Unfortunately, by the time she bought her ticket, the promotion had ended, so she had to ride with a lesser-known bus company.  James Porter contributed to another printing of the book a year later (1966).   Her work was part of The Negro in American Art, a traveling exhibition funded by the California Arts Commission. (1966). In 1968, Waddy loaned the collection of prints to the Oakland Museum.

Waddy received her Honorary Doctorate from Otis Art Institute in 1987, with the citation:

"Your strong graphic images strike us with aesthetic, emotional, and social power, and your dedication to seeking out the distinctive experience of Black artists in America has widened that power.”

In the Los Angeles Bicentennial celebrations of 1981, she was one of only 12 African American artists to be honored. She toured Europe and the Soviet Union in the late 1960s with her portfolio, Prints by American Negro Artists.