Kitty White is an anthropomorphic white Japanese Bobtail cat living in the London suburbs with her family: parents George and Mary, identical twin sister Mimmy, grandparents Anthony and Margaret, and pet cat Charmmy Kitty. Her birthday is November 1st. She is often described as five apples tall and weighing three apples, though depictions vary. Her signature look features blue overalls over a yellow shirt and a red bow on her left ear, distinguishing her from Mimmy's yellow bow. Her design deliberately lacks a visible mouth, encouraging viewers to project emotions onto her and emphasizing nonverbal communication; some interpretations suggest her mouth is hidden in her fur.

Her personality is cute, bright, sweet, pure-hearted, and tomboyish. She shows determination in pursuing goals and shares a close bond with her twin sister Mimmy, who is also her best friend. Her interests include baking cookies, collecting small and cute objects, and excelling in school subjects like English, music, and art; she aspires to become a pianist or poet. While she enjoys her mother's apple pie, her own baking skills are inconsistently portrayed across different media. Her blood type is A.

Her age and life stage vary significantly across different animated productions: she appears as a young child (kindergarten to first grade) in some series, a third-grade student in others, and an independent adult managing a home or store in more recent media. This inconsistency also affects her living arrangements, which fluctuate between residing with her nuclear family and living independently, sometimes without defined educational or occupational activities.

Relationships are central to her character. Beyond her family, she has a boyfriend named Dear Daniel and maintains friendships, including with My Melody. Owning the pet cat Charmmy Kitty further establishes her caregiver role within her universe.