- This page details Alexander Marcus in the primary universe; for the Alexander Marcus in the mirror universe see Alexander Marcus (mirror); for the Alexander Marcus in the Kelvin timeline created by Nero's temporal incursion, see Alexander Marcus (Kelvin timeline); for the Alexander Marcus in the mirror universe created by Nero's temporal incursion see Alexander Marcus (mirror) (Kelvin timeline); for the Alexander Marcus in all other alternate universes see Alexander Marcus (alternates).
Alexander Marcus was a male Human who was the father of Federation scientist Carol Marcus. Alexander was the grandfather of David Marcus. (TOS movies: The Wrath of Khan, Into Darkness)
In 2223 Marcus convinced a young man named Christopher Pike to join Starfleet. Pike received his commission four years later. (TOS movie & novelization: Star Trek Into Darkness)
- The primary universe's version of this character has never been seen or mentioned onscreen, but his existence is implied since the Kelvin timeline only begins in 2233, when Marcus was already in adulthood. The events around Marcus recruiting Pike pre-date the timeline split in 2233, however the dates given in other sources give Pike's time at the Academy as post-2233.