Rebecca Romijn has announced that in the 4th season of Star Trek: Strange New Worlds, Lt. Commander Una Chin-Riley will leave the Starship Enterprise to lead missions and take on a leadership role. Paramount+ has officially announced that the 4th season will premiere on July 23. In a statement made at CCXP Mexico, Romijn noted that the character Una will "spend more time on planets" and will lead "incredible missions".

Since the finale of Season 3 of Star Trek: Strange New Worlds aired on Paramount+ in September, many developments have taken place. Filming for the fifth and final season was completed in Toronto shortly before Christmas 2025, Star Trek: Starfleet Academy was launched in January but canceled in March 2026, and the sets for both series were dismantled and sold at auction.

Romijn expressed that Number One is now "living authentically" and has requested to "spend more time on planets" at the beginning of Season 4. The character will become more liberated and will have the opportunity to lead "incredible missions." In Star Trek: The Next Generation, the first officer of the USS Enterprise would lead the landing party while the Captain remained safely on the ship; Strange New Worlds will revive this tradition in Season 4.

In the Season 4 trailers, Number One is seen actively participating in phaser battles alongside Captain Christopher Pike (Anson Mount). In new visuals, Commander Una Chin-Riley is on missions with Officers La'an Noonien-Singh (Christina Chong) and Erica Ortegas (Melissa Navia) on planets. According to information presented by Star Trek: Strange New Worlds, Number One is a genetically engineered Illyrian, stronger and more resilient than humans, making her ideal for dangerous missions.

It is also significant that the character Una will have more screen time in Season 4. Since the show's large cast has often limited Number One to supporting roles, having the character take center stage and engage in more active missions has been a long-awaited step. More "planet" time is a positive development that fans of Star Trek: Strange New Worlds are eagerly anticipating.