Phelsuma madagascariensis is a species of day gecko that lives in Madagascar.

It is among the most widespread day geckos and is found in a wide range of habitats.

[2] With a length of up to 30.5 centimetres (12.0 in), it is also the largest day gecko in Madagascar.

[2] (The highly restricted Round Island day gecko is the only other extant species with a similar maximum length; the extinct Rodrigues giant day gecko was even larger.)

There are several subspecies: Phelsuma grandis, the Madagascar giant day gecko, was previously considered a subspecies of Phelsuma madagascariensis but has now been elevated to a full species.