Planet Names for Cats: From Mercury to Pluto (and Why They Fit)

How to Match a Planet to Your Cat (And Why Pluto Is Still a Planet for Naming)

I grew up with a brown tabby named Jupiter. He was enormous, slow, dignified, and the household's most stable presence. The name fit because my dad had been a science teacher and had a soft spot for the gas giants. What I learned from Jupiter is that planet names carry personality on their own. You don't have to explain Mars to a guest; the cat named Mars becomes a small red planet the moment you say it. This page walks through the planet pool, organized by which planet suits which cat personality.

The curated list is in the grid above. The grid pulls from the same word pool this article draws on, so any name you see here is also visible in the names list. If you are choosing between planets and another cosmic sub-theme, see the space names pillar, or jump to moon names, mythological names, or mystical names for the other sub-themes.

Why Planet Names Work for Cats

Planet names are recognizable, short, and easy to call. They come with personality already attached: Mercury is fast, Venus is soft, Mars is fierce, Jupiter is dignified, Saturn is slow, Uranus is quirky, Neptune is mysterious, Pluto is small but cheeky. A planet name slots into a household without any explanation, which makes it one of the most usable sub-themes in the cosmic pool. The trade-off is depth: there are only eight (or nine, depending on whether you count Pluto) so the pool is shallow. To expand the pool, this page also covers dwarf planets and named exoplanets, plus the major planet moons (which double as planet names for cat purposes).

Quick Picks: 8 Planet Names to Start With

• Mercury: Fast, light, witty. Suits a quick clever cat.
• Venus: Soft, female-leaning, beautiful. Suits a graceful girl cat.
• Mars: Strong, male-leaning, red. Suits an orange or red cat.
• Jupiter: Big, dignified, slow. Suits a large or senior cat.
• Saturn: Slow, classical, beautiful rings. Suits a calm cat.
• Uranus: Quirky, tilted, modern. Suits a weird cat.
• Neptune: Mysterious, deep blue, dreamy. Suits a quiet cat.
• Pluto: Small, cheeky, beloved. Suits a small cat with attitude.

Matching Recommendations by Cat Personality

The Eight Planets in the IAU Order

The International Astronomical Union (IAU) has recognized eight planets since 2006. The naming conventions follow Roman mythology for the planets and Greek mythology for the moons. This section walks through each planet with the cat-relevant angle.

• Mercury: The smallest planet and the closest to the Sun. The Romans named it after the messenger god for its speed across the sky. Short, easy to call, gender-neutral.
• Venus: The second planet, the brightest object in the night sky after the moon. The Romans named it after the goddess of love. Female-leaning, soft, recognizable.
• Earth: Our home. Rarely used as a cat name because of the round-the-house confusion, but Gaia (the Greek name) works.
• Mars: The red planet. The Romans named it after the god of war. Strong, male-leaning, fits orange or red cats.
• Jupiter: The largest planet. The Romans named it after the king of the gods. Strong, dignified, fits large or senior cats.
• Saturn: The ringed planet. The Romans named it after the god of agriculture and time. Slow, classical, beautiful.
• Uranus: The tilted planet. The Greeks named it after the sky god Ouranos. Quirky, modern, gender-neutral.
• Neptune: The deep blue planet. The Romans named it after the god of the sea. Mysterious, quiet, deep.

Pluto and the Dwarf Planets

Pluto was reclassified as a dwarf planet by the IAU in 2006, but for cat-naming purposes it is still the ninth planet in many households. The dwarf planet pool adds Ceres, Eris, Makemake, and Haumea for owners who want less common picks.

• Pluto: Small, cheeky, beloved. The Disney dog and the dwarf planet at once. Suits a small cat with outsized personality.
• Ceres: The largest object in the asteroid belt. Roman goddess of agriculture. Soft, female-leaning.
• Eris: The dwarf planet that triggered Pluto's reclassification. Greek goddess of discord. Strong, dramatic, female-leaning.
• Makemake: Named after the Rapa Nui god of fertility. Exotic, modern, gender-neutral.
• Haumea: Named after the Hawaiian goddess of fertility. Soft, female-leaning, exotic.

Planet Names by Gender

Some planet names lean male, some lean female, and a few are gender-neutral. Pick by personality, not by gender label, but here is a quick lean if you have a preference.

• Male-leaning planet names: Mars, Jupiter, Saturn, Mercury, Uranus, Pluto.
• Female-leaning planet names: Venus, Ceres, Eris, Haumea.
• Gender-neutral planet names: Neptune, Makemake, Gaia (Earth in Greek), Pluto.

Planet Moons That Double as Cat Names

Some of the most usable planet-themed names are actually the moons of the planets. The major planet moons (Titan, Europa, Ganymede, Callisto, Io, Triton, Titania, Oberon) work as planet-themed cat names even though they are technically not planets. The full moon pool lives on the moon names page; the most usable planet-moon cross-picks are listed here.

• From Jupiter: Io (volcanic, fiery), Europa (icy, elegant), Ganymede (the largest moon in the solar system), Callisto (mythological nymph, soft).
• From Saturn: Titan (the only moon with a dense atmosphere), Phoebe (a small, retrograde moon), Enceladus (icy, geysers).
• From Uranus: Titania, Oberon, Ariel, Miranda, Umbriel. Shakespearean and Pope's Rape of the Lock names.
• From Neptune: Triton (a retrograde moon, the largest).
• From Mars: Phobos (fear) and Deimos (dread), tiny and rocky.

Exoplanets and Modern Astronomy Picks

For cat owners who want a less common planet name, the exoplanet catalog (4,000+ confirmed planets as of 2026) is a deep well. The IAU has approved proper names for several hundred of them, mostly drawn from world cultures. The picks below are the most cat-usable.

• Dimidium: The first exoplanet confirmed around a sun-like star (51 Pegasi b, nicknamed Dimidium). Latin for "half". Suits a half-and-half cat.
• Spe: Latin for "hope". Soft, modern, gender-neutral.
• Musica: Latin for "music". Soft, elegant.
• Arion: A hot Jupiter exoplanet named after the Greek poet. Strong, male-leaning.
• Janssen / Copernicus / Galileo: The IAU named a star and its planets after famous astronomers. Suits cats with scholarly names.

How to Pronounce the Harder Planet Names

Most planet names are one or two syllables and easy to call. The two exceptions in the pool are Uranus (often the butt of jokes, but the pronunciation is simple: "YOO-ran-us" or "yur-AYN-us", both accepted) and Makemake ("MAH-kay-MAH-kay"). The pronunciation hint on the cat name cards gives the phonetic spelling, and you can always look up the IAU's official pronunciation guide.

Common Mistakes with Planet Names

The biggest mistake is picking a planet name that triggers the "your cat is named after a bodily function" joke (Uranus). Some owners love this; most don't. The second biggest mistake is overloading a household with similar-sounding planet names (Mars and Mercury are too close for a multi-cat home). The third mistake is picking a planet name that is so famous it overwrites the cat (Saturn, Mars). Pick a slightly less famous planet for a more distinctive cat.

Where to Go From Here

For the broader cosmic pool, see the space names pillar. For moon-only picks, see moon names for cats. For mythologically-named picks that double as planet names, see mythological cat names. The cat name generator can also produce a custom shortlist filtered to the planet or cosmic vibe.

Curated by the CatName Studio editorial team. Last updated September 2026. References: International Astronomical Union (IAU) planet naming conventions, NASA Solar System Exploration pages, IAU Working Group on Star Names (2016-2026).