He is currently the Asa Griggs Candler Professor of Mathematics at Emory University.

Ono is the son of mathematician Takashi Ono, who emigrated from Japan to the United States after World War II. His older brother, immunologist and university president Santa J. Ono, was born while Takashi Ono was in Canada working at the University of British Columbia, but by the time Ken Ono was born the family had returned to the US for a position at the University of Pennsylvania. In the 1980s, Ono attended Towson High School, but he dropped out. He later enrolled at the University of Chicago without a high school diploma. There he raced bicycles, and he was a member of the Pepsi–Miyata Cycling Team.

He received his BA from the University of Chicago in 1989, where he was a member of the Psi Upsilon fraternity. He earned his PhD in 1993 at UCLA where his advisor was Basil Gordon. Initially he planned to study medicine, but later switched to mathematics. He attributes his interest in mathematics to his father.

Ono's contributions include several monographs and over 160 research and popular articles in number theory, combinatorics, and algebra. He is considered to be an expert in the theory of integer partitions and modular forms. In 2000 he greatly expanded Ramanujan's theory of partition congruences, and in work with Kathrin Bringmann he has made important contributions to the theory of Maass forms, functions which include Ramanujan's mock theta functions as examples. In 2007 Don Zagier gave a Seminar Bourbaki address on the work of Bringmann, Ono, and Zwegers on the mock theta functions. The 2009 SASTRA Ramanujan Prize, awarded to a young mathematician under the age of 32, was awarded to Kathrin Bringmann for this joint work with Ono. Recently he and his collaborators have announced a proof of the famous Umbral Moonshine Conjecture.

Ono has received many awards for his research. In April 2000 he received the Presidential Career Award (PECASE) from Bill Clinton in a ceremony at the White House, and in June 2005 he received the National Science Foundation Director's Distinguished Teaching Scholar Award at the National Academy of Science. He has also won a Sloan Fellowship, a Packard Fellowship, and a Guggenheim Fellowship. In 2012 he became a fellow of the American Mathematical Society.

In 2011 and 2015 Ono gave TED talks.

In a joint work with Jan Bruinier, he recently discovered a finite formula for computing partition numbers.

He stars in the 2013 docudrama "The genius of Srinivasa Ramanujan".

He is profiled in the May 2014 issue of Scientific American. He was an Associate Producer and the mathematical consultant for the movie *The Man Who Knew Infinity* based on Ramanujan's biography written by Robert Kanigel.

In April 2014 Ono announced that he and two others had found a framework for the Rogers–Ramanujan identities and their arithmetic properties, solving a long-standing mystery stemming from the work of Ramanujan. The findings yield a treasure trove of algebraic numbers and formulas to access them. Ono's co-authors for this work were S. Ole Warnaar of the University of Queensland and Michael Griffin, an Emory University graduate student. Their work made world news that year and was ranked 15th among the top 100 stories of 2014 in science in *Discover* magazine.

After 15 years of focusing on the Rogers–Ramanujan identities, Warnaar had found a way to embed them into a much larger class of similar identities using representation theory. When Ono saw Warnaar's work, "It just clicked," Ono recalls. "Now we can extract infinitely many functions whose values are algebraic numbers."

In recent years, Ono has resumed athletic training as a runner, swimmer and cyclist; since 2012, he has competed in triathlons as a member of Team USA. Ken Ono now lives in Atlanta GA with his wife Erika, daughter Aspen, and son Sage.

National Security Agency Young Investigator (1997)
National Science Foundation CAREER Award (1998)
Alfred P. Sloan Foundation Research Fellowship (1999)
David and Lucile Packard Research Fellowship (1999)
Presidential Early Career Award (awarded by Clinton) (2000)
National Science Foundation CBMS Distinguished Lecturer (2003)
John S. Guggenheim Fellowship (2003)
Manasse Professor of Letters and Science, U. Wisconsin (2004–2011)
National Science Foundation Director's Distinguished Teaching Scholar Award (2005)
Hilldale Professor of Mathematics, U. Wisconsin (2008–2011)
Candler Professor of Mathematics, Emory University (2010–present)
Fellow of the American Mathematical Society (2013)
Albert E. Levy Award for Scientific Research (2014)
MAA George Polya Distinguished Lecturer (2016–2017)
International Science Film Festival Technical Award (2017)
Eleanor Main Graduate Mentor Award (2017)

Ono is on the editorial board of fourteen journals:

Annals of Combinatorics
Bulletin of the American Mathematical Society
Communications in Number Theory and Physics
Integers
International Journal of Modern Mathematics
The International Journal of Number Theory
The International Mathematical Forum
Involve
Journal of Combinatorics and Number Theory
Online Journal of Analytic Combinatorics
Proceedings of the American Mathematical Society (Managing Editor)
The Ramanujan Journal
Research in the Mathematical Sciences (Editor-in-Chief)
Research in Number Theory (Editor-in-Chief)