John O'Brien was born in Philadelphia, Pennsylvania in 1953 and graduated from the Philadelphia College of Art in 1975.

During his career, he has worked with many renowned publishers, illustrating over 100 children's books, 8 of which he also wrote.  He has illustrated publications such as The Wall Street Journal, The Washington Times, Global Finance, and Worth, and has contributed to numerous other collections, anthologies, and textbooks.  He also enjoyed a long relationship with Highlights for Kids magazine, for which he created numerous covers and interior illustrations.

John also had a long career as a cartoonist for numerous magazines, including The New Yorker, for which he created 17 covers and more than 200 interior illustrations.  His drawings have also appeared in The New York Times, Esquire, Fast Company and Omni, among others.

John resides in Delran, New Jersey during the spring and fall.  In the summer he travels to North Wildwood, New Jersey, where he worked as a lifeguard for the North Wildwood Beach Patrol from 1970 to 2015.  John spends the winter months in Miami, Florida.

He plays music both professionally and for entertainment, primarily Dixieland and Celtic.  He especially likes the banjo and the concertina, but he also plays the piano, bass and guitar.

John has a daughter, Tess, who graduated from LaSalle College in Philadelphia.