Phelsuma sundbergi, commonly called the La Digue day gecko, Mahé day gecko, or Seychelles giant day gecko, is a species of lizard in the family Gekkonidae. The species is endemic to Seychelles and has three subspecies.
The specific name, sundbergi, is in honor of Swedish amateur ichthyologist Henrik Sundberg.
The natural habitats of P. sundbergi are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, subtropical or tropical moist montane forests, plantations, rural gardens, urban areas, and introduced vegetation.
P. sundbergi is threatened by habitat loss.
P. sundbergi is oviparous.
Three subspecies are recognized as being valid, including the nominotypical subspecies.