Can fancy goldfish live with mollies?

Verdict
No

No. Fancy goldfish and mollies should not share a tank. Fancy goldfish are coldwater animals (65–74°F); mollies need 72–82°F. They overlap only at 72–74°F, the edge of both ranges.

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–74°Fancy goldfish 65–74°Molly 72–82°
The green band is the temperature range both can live in.
456789Both: 7.5–8Fancy goldfish 7–8Molly 7.5–8.5
The green band is the pH both tolerate.

Size to scale

Fancy goldfish · 6 inMolly · 4 in0"1"2"3"4"5"6"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

Fancy goldfishMolly
Temperature65–74 °F72–82 °F
pH7–87.5–8.5
Adult size6.0 in4.0 in
Minimum tank30 gal20 gal
TemperamentPeacefulPeaceful
Swims atAll levelsTop
GroupAlone or in pairsGroups of 3+
DietOmnivoreOmnivore

Better tank mates for fancy goldfish

All fancy goldfish tank mates

Better tank mates for mollies

All molly tank mates

Questions

Can fancy goldfish live with mollies?

No. Fancy goldfish and mollies should not share a tank. Fancy goldfish are coldwater animals (65–74°F); mollies need 72–82°F. They overlap only at 72–74°F, the edge of both ranges.

What temperature suits both fancy goldfish and mollies?

72–74 °F. Fancy goldfish need 65–74 °F, mollies need 72–82 °F.

What size tank do fancy goldfish and mollies need together?

At least 30 gal, set by the fancy goldfish. Add space for each extra fish.