This is a timeline of significant events in comics in the 1900s.
1900
U.S. publications
- March 11: first publication of Happy Hooligan by Frederick Burr Opper in the Hearst newspaper Sunday pages.
1904
U.S. publications
- January 2: first appearance of Major Ozone's Fresh Air Crusade by George Herriman, syndicated by World Color Printing Co.
- February 14: first appearance of Little Jimmy by Jimmy Swinnerton in the New York Journal.
- July 24: first appearance of Little Sammy Sneeze by Winsor McCay in New York Herald.
- September 10: first appearance of Dreams of the Rarebit Fiend by McCay under the pseudonym Silas, in Evening Telegram.
1905
Chinese publications
- Unknown date: Journal of Current Pictorial
European publications
- February 2: first appearance of Bécassine drawn by Joseph Pinchon, in La Semaine de Suzette.
U.S. publications
- January 8: first appearance of The Story of Hungry Henrietta by Winsor McCay.
- June 26: first appearance of A Pilgrim’s Progress by McCay.
- October 15: first publication of Little Nemo in Slumberland by McCay in New York Herald.
- Unknown date: a collection of McCay's Dreams of the Rarebit Fiend strips is published by the Frederick A. Stokes Company of New York.
1908
- Harold R. Heaton joins the Inter-Ocean newspaper as an editorial cartoonist.
1909
U.S. publications
- November 1: first appearance of The Umbrella Man by John Hager for the Seattle Daily Times, appearing on the front page as a supplement for the weather. Not titled as the Umbrella Man, but called that May 3, 1913 under a section called "Features of Today's Paper".