No. The Nintendo GameCube AV cable does not work with the Sega Dreamcast.
Why They're Incompatible
Different connector shapes: GameCube uses a proprietary rectangular digital/analog port. Dreamcast uses a unique trapezoidal "A/V" port.
Different signal wiring: Even if you forced a physical connection, pinouts for video (composite/S-Video/RGB), audio, and ground don't match.
Signal format: Dreamcast natively outputs RGB (SCART) and VGA (with box). GameCube outputs composite/S-Video (NTSC) or RGB (PAL) — but on different pins.
Correct Dreamcast Cables
Standard Dreamcast AV Cable: Composite (yellow/red/white) — included with console.
Dreamcast VGA Box / Cable: 640x480 VGA output — best for modern monitors (requires VGA input).
Dreamcast Component Cable: YPbPr (red/green/blue + audio) — rare, expensive, best analog quality.
Dreamcast SCART Cable (RGB): Standard in Europe — excellent quality on SCART-equipped TVs/upscalers.
Buy the cable matching your display's best available input. Don't try to adapt GameCube cables—it won't work and could damage ports.
