The standard uniform and protective gear utilized by Imperial Knights was known as Imperial Knight armor. This armor's design and implementation occurred between 43 ABY and 127 ABY, specifically after Jagged Fel became Emperor of the Fel Empire but before the Sith–Imperial War. The armor featured a crimson and black color scheme and was constructed to endure impacts from lightsabers. It incorporated cortosis gauntlets capable of temporarily disabling lightsabers. Alongside Imperial Knight lightsabers, this armor served as a defining characteristic of an Imperial Knight, although they were known to wear civilian clothing when necessary. A modified version of Imperial Knight armor was worn by Emperor Roan Fel, and Master armorer Hogrum Chalk created specialized armored suits to sustain the lives of critically injured Imperial Knights.
The crimson suit of armor that comprised Imperial Knight armor was crafted from the same material used in the armor of the Dark Lord of the Sith Darth Vader. It was reinforced with fine phrik filaments, enhancing its resistance to lightsaber strikes. The Imperial insignia was displayed on the left shoulder pad and right gauntlet; the gauntlet itself was made of pure cortosis, which could render a lightsaber blade ineffective for several minutes upon contact. A black hood and cape were also part of the standard uniform. Roan Fel typically wore a more ornate version of this armor, accompanied by a royal cape. However, during hazardous missions, such as the one on Agamar in 137 ABY, he opted for the more practical and versatile standard armor. Imperial Knights, being highly skilled Force users, were adept at maximizing the effectiveness of their armor.
The Imperial Knights' master armorer designed specialized, life-sustaining suits for Imperial Knights who had sustained severe injuries. By 137 ABY, Hogrum Chalk had engineered at least two such suits, including one for Azlyn Rae following her injuries inflicted by Karness Muur's spirit during the Battle on Had Abbadon.
The Imperial Knight armor was created and adopted as the standard attire for Imperial Knights sometime after Jagged Fel assumed leadership of the Fel Empire around or after 45 ABY, and before the Sith–Imperial War, which spanned from 127 ABY to 130 ABY. All Imperial Knights wore this armor, with Emperor Roan Fel sporting a modified version, throughout the duration of the Second Imperial Civil War.
While the uniform was typically worn while on duty, Imperial Knights would dress in ordinary clothing when the situation required. During her mission to the Hidden Temple, and later to Had Abbadon, Azlyn Rae remained in her bounty hunter's attire, as she was undercover and presumably without her standard armor. Treis Sinde donned crimson armored gear for underwater use while aiding rebels on Mon Calamari, and he and Sigel Dare wore plainclothes during their covert mission to Dac.
In 140 ABY, a year following his departure from the Imperial Knights, Jao Assam was seen wearing Imperial Knight armor that was colored white.
Dark Horse comics designed Imperial Knight armor for the Star Wars: Legacy comic book series. The armor bears a strong resemblance to that of the Emperor's Royal Guard, particularly the armor worn by Kir Kanos in the Star Wars: Crimson Empire comic book series, also by Dark Horse, as Kanos was often depicted without a helmet. The cortosis gauntlets on the armor are similar to the vambraces worn by Zayne Carrick in the Star Wars: Knights of the Old Republic comic book, but their functions differ. Carrick's vambraces could deflect lightsaber strikes, while the cortosis gauntlets of Imperial Knights could temporarily deactivate lightsabers. Errors in penciling or coloring sometimes resulted in variations of the standard Imperial Knight armor in the comic, such as Roan Fel's gauntlets being drawn without gloves in a panel of Legacy (2006) 13.
Jan Duursema's artwork of the Imperial Knight armor used the work of costumer Thomas J. Spanos as a reference. Spanos also served as the model for the appearance of Imperial Knight Ganner Krieg.