After elementary and high-school education in Albany, Kaler earned his A.B. at the University of Michigan in 1960. He attended graduate school at the University of Michigan (1960–61), at Christian-Albrechts-Universität zu Kiel (Germany, 1961–62), and UCLA (1962–64), where he also obtained his Ph.D. in Astronomy 1964. His thesis advisor was Lawrence H. Aller.
Kaler started his professional career with appointments as a research and teaching assistant at the University of Michigan from 1958 to summer 1960. In 1961 he worked as an astronomer with the United States Naval Observatory. In 1964 he was appointed as an assistant professor of Astronomy by the University of Illinois, and promoted to associate professor in 1968 and to a full professor position in 1976 (all at University of Illinois). Since 1995 he is Campus Honors Faculty. In 2003 he retired to become professor emeritus at the University of Illinois.
Kaler published over 120 papers. Examples include work on
He has held Fulbright and Guggenheim Fellowships, and has been awarded medals for his work from the University of Liège in Belgium and the University of Mexico. He gave the Armand Spitz Lecture to the Great Lakes Planetarium Association and the Margaret Noble Address to the Middle Atlantic Planetarium Society. In 2003 he received the 2003 Campus Award for Excellence in Public Engagement by the University of Illinois.
Jim Kaler has written for a variety of magazines, and was a consultant for Time-Life Books. He has long appeared on Illinois television and radio. In addition to two textbooks and three audio courses, he published several books, including
His science WWW-star database "STARS" has scored more than 3.4 million visitors since its release.