Landis was born in Detroit, Michigan and lived in Virginia, Maryland, Philadelphia, and Illinois during his childhood. His senior education was at New Trier High School, Winnetka, Illinois. He holds undergraduate degrees in physics and electrical engineering from the Massachusetts Institute of Technology (MIT) and a PhD in solid-state physics from Brown University. He is married to science fiction writer Mary A. Turzillo and lives in Berea, Ohio.

After receiving his doctorate at Brown University, Landis worked at the NASA Lewis Research Center (now Nasa Glenn) and the Ohio Aerospace Institute before accepting a permanent position at the NASA John Glenn Research Center, where he does research on Mars missions, solar energy, and advanced concepts for interstellar propulsion. He holds eight patents, and has published more than 300 scientific papers in the fields of astronautics and photovoltaics. He was a member of the Rover team on the Mars Pathfinder mission, and is a member of the science team on the 2003 Mars Exploration Rovers mission.

In 2002 Landis addressed the annual convention of the American Association for the Advancement of Science on the possibilities and challenges of interstellar travel in what was described as the "first serious discussion of how mankind will one day set sail to the nearest star". Dr. Landis said, "This is the first meeting to really consider interstellar travel by humans. It is historic. We're going to the stars. There really isn't a choice in the long term.". He went on to describe a star ship with a diamond sail, a few nanometres thick, powered by solar energy, which could achieve "10 per cent of the speed of light". In 2005-2006, he was the Ronald E. McNair Visiting Professor of Astronautics at MIT.

Landis has commented on the practicalities of generating oxygen and creating building materials for a future Moon base in New Scientist, and on the possibilities of using readily available metallic iron to manufacture steel on Mars.

In the field of science fiction, Landis has published over 70 works of short fiction, and two books. His work mixes high science and technology with human emotion. He won the 1989 Nebula Award for best short story for "Ripples in the Dirac Sea" (Asimov's Science Fiction, October 1988), the 1992 Hugo Award for "A Walk in the Sun" (Asimov's Science Fiction, October 1991), and the 2003 Hugo for his short story "Falling Onto Mars" (Analog Science Fiction and Fact, July/Aug 2002). His first novel, Mars Crossing, was published by Tor Books in 2000, winning a Locus Award, and a short story collection, Impact Parameter (and Other Quantum Realities), was published by Golden Gryphon Press in 2001 and named as noteworthy by trade magazine Publishers Weekly. He has also won the Analog Analytical Laboratory Award for the novelette The Man in the Mirror (2009) and Rhysling Awards for his poems Christmas, after we all get time machines (2000) and Search (2009). In 2009, he published a collection of poetry, Iron Angels.

He attended the Clarion Workshop in 1985, with other emerging SF writers such as Kristine Kathryn Rusch, Martha Soukup, William Shunn, Resa Nelson, Mary Turzillo and Robert J. Howe, and taught at the Clarion Workshop in 2001. Landis has also written non fiction and popular science articles, encyclopedia articles and columns for a large range of publications, including Analog Science Fiction and Fact, Space Sciences, Asimov's Science Fiction, Spaceflight, and Science Fiction Age.