Jill's depiction over the course of the series has gone through minor changes while still maintaining a level of consistency. All of her default outfits are variations of blue. Her dress attire ranges from tactical gear to sleek and sexy. In the original Resident Evil her hair was long, but tucked into her beret while in the remake, Resident Evil 3: Nemesis, Resident Evil: The Umbrella Chronicles, and Resident Evil: Operation Raccoon City her hair was in a bob. Resident Evil 5 marks the introduction of Jill going from brunette to blonde as a result of experimentation done on her body. In her most recent appearance, Jill is shown to have grown out her hair and tie it up in a ponytail similar to Claire Redfield. In Resident Evil: Revelations, a prequel to Resident Evil 5, her hair is brown again but still in a ponytail.
Jill's standard and most well-known outfit is a pair of blue assault pants with a light blue formfitting shirt and shoulder/neck armor, completed with a blue beret on her head. In addition to her S.T.A.R.S. uniform in the first game, Jill wears a casual outfit consisting of jeans and black shirt. In Resident Evil: Director's Cut, she wears a sleeveless blouse with the S.T.A.R.S logo on the back along with jeans and boots as a default outfit in the game's Arranged Mode. The Sega Saturn version of the first game also featured Jill in an alternate version of her S.T.A.R.S. uniform.
In Resident Evil 3: Nemesis, she wears a blue tube top, black mini-skirt, white sweater wrapped around her waist, and brown tactical boots as her default outfit. This is also a well-known outfit and is the outfit worn by Sienna Guillory in the second live action film. She has a total of five alternate outfits (eight in later versions), including her original S.T.A.R.S. uniform, a police mini-skirt, a biker outfit, and a disco outfit. The Resident Evil remake featured her standard Resident Evil 3: Nemesis outfit and a new military outfit.
In Resident Evil: Deadly Silence (the Nintendo DS port of the original), Jill wears her original casual outfit, as well as a revealing policewoman uniform in the game's Rebirth Mode.
In Resident Evil: Revelations, Jill wears a blue sweatshirt and grey pants early in the game and changes to a blue and black BSAA wetsuit, with black diving boots for her mission to the Queen Zenobia.
In Resident Evil 5, Jill sports a pale blue B.S.A.A. uniform during her mission to apprehend Spencer. This outfit bears some resemblance to her S.T.A.R.S. uniform, with a blue cap replacing her beret. After being taken by Wesker, she is stripped of her uniform and fitted with a skin tight indigo blue and black battle suit. Her disguise over the battle suit in Kijuju includes a long cloak and a beak-shaped mask. Because of the experiments performed on Jill's body a number of changes occurred. Her time in cryostasis caused a pigmentation abnormality to her hair and skin transforming Jill from a brunette into a pale blonde. An external device was embedded into Jill's chest to brainwash her into an obedient super soldier for Wesker and Excella. Once the device was removed it left a scar in the center of her chest where it had once been attached (not shown in Mercenaries).