The UNSC Maelstrom was a UNSC Navy vessel that was present at the Second Battle of Harvest on March 1, 2526. It was destroyed by the single Covenant vessel's fifth and final salvo along with the UNSC Waterloo and UNSC Excellence during Battle Group X-Ray's last desperate attempt to win the battle.
- The ship is likely named for a type of very powerful whirlpool.
- Halo: Evolutions - Essential Tales of the Halo Universe
- The Impossible Life and the Possible Death of Preston J. Cole (First appearance)