"Strange New Worlds" exists in a canon sandwich, bookended by the events of "Star Trek: Discovery" and Captain James T Kirk's legendary five-year mission. As a result, many of the Starfleet officers (and a few antagonists) who make their mark in the Original Series are already on active duty in the prequel show "Strange New Worlds".
So, as Captain Pike and co's third season warps onto Paramount+, we've assembled a roster of every character from the Original Series (along with a few from the Animated Series and the Kirk era movies) whose younger selves have shown up in "Strange New Worlds".
