"Writing a science fiction story is fun, not work. ... the fun... lies in treating the whole thing as a game. ... the rules must be quite simple. They are; for the reader of a science-fiction story, they consist of finding as many as possible of the author's statements or implications which conflict with the facts as science currently understands them. For the author, the rule is to make as few such slips as he possibly can ... Certain exceptions are made [e.g., to allow travel faster than the speed of light], but fair play demands that all such matters be mentioned as early as possible in the story..."

• Abyormen — A planet circling a dwarf star (Theer), which in turn circles a blue giant. This produces a hot and a cold season, each of 65 years' duration. The native intelligent life forms undergo a seasonal mass death. From Cycle of Fire.
• Dhrawn — A high-gravity world settled by Mesklinites in Star Light.
• Habranha - A planet that is tidally locked with its sun, such that the far side is a mix of solid CO2, solid methane, and ice, and the other side completely ocean, in Fossil.
• Hekla — An ice-age planet in Cold Front (short story, Astounding July 1946).
• Kaihapa — An uninhabited ocean planet, twin of Kainui, in Noise.
• Kainui — An inhabited ocean planet in Noise.
• Mesklin ... A planet with ultra-high gravity (up to 700 g) in Mission of Gravity. Clement later corrected his model of Mesklin and determined that the maximum surface gravity would be "only 250 gravities".
• Sarr — An extremely hot planet with an atmosphere of gaseous sulphur ('air') and liquid copper sulphate ('water') in Iceworld
• Tenebra — A high-gravity world with a corrosive atmosphere in Close to Critical.
• Enigma 88 - A small planet near ? Carinae in Still River. The interior of the object is honeycombed with caves, due to evaporation of accreted ice-rich planetoids. Unusually for Clement, Enigma's structure is not fully consistent with the laws of physics.

• Needle (1950), ISBN 0-380-00635-9
• Iceworld (1953), ISBN 0-345-25805-3
• Mission of Gravity (1954), ISBN 0-345-31622-3
• The Ranger Boys in Space (1956) (for children)
• Cycle of Fire (1957), ISBN 0-345-24368-4
• Close to Critical (1958), ISBN 0-345-24508-3 (magazine publication in 1958, book in 1964)
• Space Lash (1969) Short story collection (also printed as Small Changes)
• Star Light (1971), ISBN 0-345-02361-7 (sequel to Mission of Gravity)
• Ocean on Top (1973), ISBN 1-4510-1057-5
• Through the Eye of a Needle (1978), ISBN 0-345-25850-9 (sequel to Needle)
• The Nitrogen Fix (1980), ISBN 0-441-58116-1
• Still River (1987), ISBN 0-345-32916-3
• Fossil (1993), ISBN 0-88677-573-6
• Half Life (1999), ISBN 0-312-86920-7
• The Essential Hal Clement, Volume 1: Trio for Slide Rule and Typewriter (1999), ISBN 1-886778-06-X
• The Essential Hal Clement, Volume 2: Music of Many Spheres (2000), ISBN 1-886778-07-8
• The Essential Hal Clement, Volume 3: Variations on a Theme by Sir Isaac Newton (2000), ISBN 1-886778-08-6
• Heavy Planet (2002), ISBN 0-7653-0368-X (collection of Mesklin stories)
• Noise (2003), ISBN 0-7653-0857-6