No. Reverse osmosis water is produced by pressure and a membrane, distilled water by boiling and condensation, and the results are not identical even though both taste flat. Reverse osmosis leaves a small residual load of dissolved solids, which matters for a few appliance and laboratory uses and matters not at all for drinking.
Different machines, similar looking result
A membrane rejects dissolved solids by forcing water through pores that most ions cannot cross, and the rejected fraction leaves continuously down a drain line. A still leaves those solids behind in a boiler and carries only vapor across. Because neither process is perfect, both outputs are described by how much is left rather than by purity: reverse osmosis typically leaves a small measurable residue, distillation leaves less.
Where the difference actually bites
Anywhere a residue is unacceptable, the specification says distilled and means it. Steam irons and humidifiers scale from whatever is left behind, CPAP humidifier chambers are specified as distilled by their makers, and lead acid batteries want nothing dissolved at all. Substituting reverse osmosis water in those uses is a judgment call against the manufacturer's instruction, and the manufacturer is the one who honors the warranty.
Where they are interchangeable
For drinking, cooking, ice, coffee, pet bowls and topping up a kettle, the difference between the two is not meaningful. Both are low in minerals, both taste flat compared with mineral rich tap water, and both benefit from a remineralizing stage if you dislike that flatness. In a household context the practical question is not which is purer but which you can get on demand from a faucet.
Choosing one for the house
A plumbed reverse osmosis system delivers continuously to a dedicated faucet and needs no electricity, at the cost of drain water and cartridge changes. A still occupies counter space, runs a heating element for hours per batch and needs descaling, but needs no plumbing at all. Our reverse osmosis buying guide compares system sizes and stage counts if the plumbed route is the one that fits your kitchen.
Questions people ask about is reverse osmosis water distilled
Can I use RO water instead of distilled in an iron or humidifier?
It is closer than tap water but not equivalent, and the residual dissolved solids can still leave scale. Follow the appliance maker's instruction.
Which has fewer dissolved solids?
Distilled, usually. A membrane rejects most dissolved solids but not all, while distillation leaves nearly everything nonvolatile in the boiler.
Do both taste the same?
Both taste flat because the minerals that give water body are gone. Many people cannot tell them apart in a glass at the same temperature.
Is one better for drinking?
Neither has a drinking advantage for an ordinary household. Availability and running cost decide it, and a plumbed system wins on convenience.