Welcome to Halo Answers. What would you like to know?

John. (Master Chief) Sierra is the NATO Phonetic Alphabet's word for S, and in Halo, it stands for SPARTAN. 117 is John's SPARTAN tag. His complete SPARTAN name and title is Master Chief Petty Officer John-117.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.