In 2018, former game director for Star Wars: The Old Republic, James Ohlen, said in an interview with GameInformer that he regretted having not pushed it to be "Knights of The Republic online" as opposed to making it traditional in the style of World of Warcraft, referring to it as "Star Wars World of Warcraft."

Part of the inspiration for the villain Arcann's design was from a talk by the director of the Clone Wars TV series about how all of the Star Wars villains are always dressed in black in a certain way. They decided to make him dressed in all white with the look of a prince.

The Sith Warrior companion, Vette, and the Smuggler companion, Risha, both had a sisterly relationship during their childhood. Both tell stories about their former lives with a pirate Nok Drayen. Vette mentions Risha by name and Risha speaks of a Twi'lek girl she used to treat like a sister.

The design of the vehicle mount the Prinawe Collective is in reference to the T-65 X-Wing starfighter from the original Star Wars film trilogy (set approximately 3,000 years after the events of Star Wars: The Old Republic). The vehicle features a red and gray paint design and dark gray nose and red thruster fire similar to the X-Wing's, a blue dome on the hood similar to R2-D2's dome, and on the control screen the X-Wing's targeting computer from the Death Star trench run.

The vehicle was given away to attendees at the 2015 Star Wars: The Old Republic Cantina Tour at Gamescom.

A scene which was cut from the trailer "Sacrifice", for the expansion "Knights of the Fallen Empire", showed Spoiler:Darth Malgus frozen in carbonite, revealing his fate after the events of the "The False Emperor" flashpoint.

As part of the release of the Gree Event, the Republic base at the south end of the Western Ice Shelf on the planet Ilum was abandoned, leaving dead bodies and the "Fray Landing Memorial". The associated codex entry commemorates the Republic soldiers who died fighting Imperial soldiers early during the war. This refers to the early stages of the game, where Imperial players outnumbered Republic players, and were able to push their way into the base, where the Imperials continuously killed the defenders.

A Special Education teacher named Lyobel was able to connect with her student, who had autism, by learning MMO terminology and playing through Star Wars: The Old Republic with him. BioWare heard about the story and sent both the student and teacher signed posters.

There are two easter eggs based on the Saturday Night Live sketch "A Night at the Roxbury" which can be found in different locations. Both show the NPCs mimicking the same actions from the sketch including bobbing their heads, trying to pick up women and wonder who between the two guys the girl wants.

The first instance can be seen in Nem'ro's Palace on Hutta where two bar patrons are seen watching a Twi'lek pole dancing. The second is aboard Carrick station in the VIP lounge where two guards are close to a group of dancers and follow the same routine from the sketch.

Star Wars: The Old Republic holds the world record for the "Largest Entertainment Voice Over Project". The game features over 200,000 lines of dialogue spoken by over a hundred voice actors.

In Nem'ro's Palace on Hutta, there's a Wookiee seen playing a board game with a dismantled gold C2 droid.

This is a reference to the scene in Star Wars Episode IV: A New Hope where Chewbacca is playing Dejarik, the hologame, against R2-D2 with C-3PO watching and the famous line "Let the Wookiee win".

In Nem'ro's Palace on Hutta, there's a Human smuggler named Han Duo seen sitting with a Rodian named Greepo.

This is a reference to the scene in Star Wars Episode IV: A New Hope where Han Solo encounters Greedo in the Mos Eisley cantina.

During development, the writers were considering the idea of a Killik companion, however they thought it would not fit with the story. Ultimately the idea was dismissed, but it inspired the Imperial Agent class companion Vector Hyllus, a human Killik Joiner.

In Star Wars: The Old Republic, aboard the command deck of the dreadnought the Ziost Shadow there's a Sith Lord pacing back and forth in front of a group of bounty hunters.

This is a reference to the scene in Star Wars Episode V: The Empire Strikes Back where Darth Vader is recruiting the bounty hunters to find the Millennium Falcon. The characters in the game also closely resemble those from the film: a Human with facial wrappings (Dengar), an assassin droid (IG-88), an individual in Mandalorian armor (Boba Fett), a robust war droid (4-LOM), a Gand (Zuckuss), and a Trandoshan (Bossk).