Born in Spring Creek, Pennsylvania. Johnson's youthful interest in cartooning had the support of his family after he won an Erie Dispatch Herald cartoon contest: "I think I was 11 years old. And then I won a newspaper cartoon drawing contest, and I think the prize was two or three tickets to Peck's Bad Boy, and that got my dad to thinking, and he gave me a $28 correspondence course. I went through that and worked on the high school yearbook all the time. I did lots of drawings there. At 13, I sold my first cartoon for money to a railroad magazine. It paid me $10 a month for years and years."
He began hanging around the Chicago Tribune offices when he was 17. After graduating from high school in 1923, he attended the Chicago Academy of Fine Arts for three months. He dropped out and became Frank Willard's assistant at the Tribune two months after Willard launched Moon Mullins in 1923. Johnson worked at the Tribune as a color artist and sports illustrator.
When he was 19, he was hired by Joseph Patterson to do a cowboy strip, Texas Slim, and he was promoted by the Tribune as the youngest cartoonist in American newspapers. Syndicated beginning August 30, 1925, Texas Slim ran for three years, and Johnson launched another strip, Lovey-Dovey in 1932. On Moon Mullins, after starting on the lettering and backgrounds, Johnson gradually progressed to the point where he was handling the entire operation.
On March 31, 1940, he revived Texas Slim as a Sunday half-page in Texas Slim and Dirty Dalton (with the companion strip, Buzzy), which ran for 18 years. It was only after Willard's death that he began signing Moon Mullins. When Willard died January 11, 1958, the Chicago Tribune New York News Syndicate hired Johnson as Willard's logical successor. Johnson recalled, ''Texas ran until 1958 when I took over Moon completely. Up to then I was working on both Moon and Texas and some advertising work, and taking some time off to eat and sleep."
Like Willard, Johnson had a natural gift for funny, slangy dialogue. He stayed with the strip until it concluded in 1991. In 1978, his son, Tom Johnson, signed on as his assistant (drawing the Sunday page and assisting on the dailies). Ferd Johnson worked on Moon Mullins for 68 years–a stint that probably stands as the longest tenure of an artist on a single feature in the entire history of American comics.
Willard and Johnson traveled about Florida, Maine and Los Angeles, doing the strip while living in hotels, apartments and farmhouses. At its peak of popularity during the 1940s and 1950s, the strip ran in 350 newspapers. According to Johnson, he had been doing the strip solo for at least a decade before Willard's death in 1958: "They put my name on it then. I had been doing it about 10 years before that because Willard had heart attacks and strokes and all that stuff. The minute my name went on that thing and his name went off, 25 papers dropped the strip. That shows you that, although I had been doing it 10 years, the name means a lot."
In 1989, Ferd Johnson reflected on his long career, beginning with his initial encounter with Frank Willard when he was in art school:
- The owner of the school knew Willard and got him to teach a cartoon class up there. He did it for two weeks and couldn't take it anymore. Meantime, he saw all the work, and he thought I had something, and he invited me up to the Tribune. I stood around there for hours watching him work. He finally turned around and said, "Ferd, if you're going to hang around here all this time, I'm going to put you to work." So I got a job as assistant at 15 bucks a week. I wrote home, and I said, "Don't send me any more money. I've got it made."... The Tribune had a bunch of cartoonists there. They were the best in the country at the time, so if I got into trouble, I'd ask them. They were great to me: Chester Gould (Dick Tracy) was one; Harold Gray (Little Orphan Annie); Sydney Smith (The Gumps). Frank King (Gasoline Alley) was right next to us... But the guys couldn't get any work done down there. There were card games, shooting craps–so they started working at home, and then they started spreading out over the country. A cartoonist can be wherever there is a mailbox... Ever since I was a kid I sketched. Frank King told me, "If you want to learn how to draw, get a sketchbook. Go out and sketch everything. Come back and try to repeat it from memory. If it doesn't work, keep going back and forth." Those old-time cartoonists could do that. There's a guy named Gaar Williams who had an office next to ours. He could draw anything. If I was stuck, I wouldn't have to go look up anything. I'd show it to him, and he'd draw it for me... I work two or three hours. I get in around 9am or 9:30am and leave at noon. That's just the drawing part. The ideas are at home, wherever I am. Most people retire at 65. I wouldn't think of retiring. It's something to do. It's fun... I know how Moon thinks. It's not like Plushbottom thinks or all the other characters. It's like a stage play almost.
Johnson continued to draw and paint after he moved into a retirement home in Irvine, California in 1995, and he died 15 months later. Doris, his wife of 57 years, whom he met in art school in Chicago, died in 1986. Johnson was survived by his younger brother, George H. Johnson of Portland, Oregon; his son, Tom, and his wife Anne of Newport Beach; four grandchildren and one great grandson.
Ferd Johnson received a ComicCon International Inkpot Award in 1993.