The whale was given the name Porphyrios by Byzantine sailors; the name is sometimes alternatively rendered as Porphyrius, Porphyrion, Porphyry or Porphyrio and its origin is not clear. Common hypotheses on the name include it being derived from the contemporary charioteer Porphyrius or from the mythological giant Porphyrion, who waged war against the gods of Greek mythology. Anthony Kaldellis suggested in 2010 that the name of the whale alluded to the imperial purple and was "a sign of the respect in which the whale was held". This idea was also supported by Sian Lewis and Lloyd Llewellyn-Jones in 2018, who believed the name alluded to the color of royalty and was a sign of great awe for the whale.
In 1996, James Allan Stewart Evans suggested that the name was a reference to the color of the whale's skin. Porphyra meant a deep purple color in Greek and Porphyrios might have had dark-wine colored skin. This was further supported by John K. Papadopoulos and Deborah Ruscillo in 2002, who believed the name simply meant "purple". Daniel Ogden in 2008 also supported the idea that Porphyrios evoked the color of the whale, believing that the name was best interpreted as "purple boy"
