The main cast reprises the Kelvin timeline roles from prior films without race or gender swaps to established characters. New additions include Idris Elba as the alien antagonist Krall and Sofia Boutella as Jaylah, both original figures integrated into the plot of Federation exploration versus a mysterious enemy.

The sole notable addition is a brief, non-central scene depicting Hikaru Sulu (John Cho) with a husband and daughter, marking the first on-screen gay couple in a Star Trek film; this was a deliberate sexuality adjustment to the character despite objections from original actor George Takei, who preferred it apply to a new crew member. Director Justin Lin discussed sustaining ethnic diversity in Hollywood in interviews, but the film's premise, action sequences, and themes of unity against external threats remain rooted in classic storytelling without lectures on systemic oppression or identity politics. Audience reception showed no notable review-bombing or 'go woke go broke' campaigns specific to this entry, unlike later series, confirming the elements stayed incidental and did not drive narrative or character arcs.