2D or 2-D may refer to:

• Two-dimensional space
• Two-dimensional Euclidean space
• 2D geometric model
• 2D computer graphics
• 2D animation, or traditional animation
• Two-dimensional correlation analysis

• 2-D (character), a member of the virtual band Gorillaz
• Index finger, the second digit (abbreviated 2D) of the hand
• Oflag II-D, a prisoner-of-war camp
• Stalag II-D, a prisoner-of-war camp
• Transcription factor II D
• Two Dickinson Street Co-op, a student dining cooperative at Princeton University
• Nintendo 2DS, the third iteration in the Nintendo 3DS line, released in 2013
• New Nintendo 2DS XL, the sixth iteration in the Nintendo 3DS line, released in 2017 and a larger version of the 2DS
• 2degrees, New Zealand telecommunications provider
• Twopence (British pre-decimal coin), routinely abbreviated 2d.

• D2 (disambiguation)
• IID (disambiguation)