Edward W. Scripps, a renowned journalist, and William Emerson Ritter, a California zoologist, founded Science Service in 1921 with the goal of keeping the public informed of scientific achievements. Scripps funded the project and Ritter served as the first scientific director.

Although Scripps died in 1926, Watson Davis continued to lead the editorial staff of the Science News-Letter. That year, this simple newsletter attracted enough readers that the staff decided to reformat it to be a magazine. Filling 14 mimeographed pages, the magazine featured articles on astronomy, pneumonia vaccines, soil chemistry, and more. It quickly grew into a primary source of science news, eliciting numerous requests from libraries, schools, and individuals for direct access to the reports. As a printed publication Science News-Letter reported on the early days of atomic energy, the beginnings of modern genetics, and many other developments. Its solid coverage helped make science reporting acceptable and respectable in both newspaper and science circles.

Over the next two decades, Science Service also broadcast news on Radio News of the Week. As parts of its mission to educate the public about science, Science Service launched the Things of Science program in November of 1940. Subscribers received monthly kits on a variety of science-related topics.

In 1941, Science Service collaborated with the American Institute of the City of New York to create science clubs across the United States. The next year, Science Service and Westinghouse held the first Science Talent Search for high school seniors in the United States. 

The Science Talent Search (STS) is America's oldest and most highly regarded science contest for high school seniors.  Created in 1942 as a means for encouraging talented high school students to pursue a career in science or engineering, the Science Talent Search has become an American institution.  Nearly six decades since its beginning, the STS has recognized almost 3,000 finalists with $4 million in scholarships.  Alumni of the STS include holders of more than 100 of the world's most coveted science and math honors.  These include three National Medal of Science winners, nine MacArthur Foundation Fellows, two Fields Medalists and six Nobel Laureates.

After eight years of success with the talent search, Science Service decided to launch the National Science Fair for high school winners of local and regional science fairs, first held in Philadelphia in 1950. This annual fair was nurtured into the International Science and Engineering Fair (ISEF). It has become the world's largest pre-college celebration of science and the world's only international science competition for students in grades 9 through 12. Dedicated to encouraging innovation, many corporate, professional, and governmental sponsors unite to present awards annually to ISEF finalists.

The Science News-Letter was renamed Science News in 1966 and its online component, www.sciencenews.org was launched in 1996. It remains the only weekly newsmagazine of science for a general audience published in the United States. 

Both the Science Talent Search and the International Science and Engineering Fair received title sponsorship from Intel in 1998.

Beginning in 1999, Science Service partnered with Discovery Communications, Inc. to launch a new science tradition, the Discovery Channel Young Scientist Challenge, now known as the SSP Middle School Program.  A program that celebrates the abilities of 5th - 8th grade science fair winners, the program enables middle schoolers to participate in a national science competition that emphasizes the student's ability to communicate about science.

In 2003, Science Service launched its online Web site, Science News for Kids (www.sciencenewsforkids.org).  This freely accessible online journal provides interactive interfaces and science news to children of all ages, but targeted to ages 9 to 14.  It attracts over 1 million visitors annually.