High-resolution calibrated reflectance spectra (350-2500 nm) of samples of penguin guano, collected on Signy Island, Antarctica, between November 2014 and January 2015. Most samples are from Adélie penguins, though some Chinstrap and Gentoo penguins are also included. A few samples of penguin stomach contents, consisting of partially digested krill and fish, are also included. All samples have accompanying photographs. A peer-reviewed paper describing the data collection methods and interpretation of the results is currently under review.