Can You Play Nintendo DS Games on a PSP?

No. The systems are fundamentally incompatible:

• Cartridge shape/size: DS cards (slot-1) vs. PSP UMD / Memory Stick.
• CPU architecture: DS = dual ARM (ARM9 + ARM7); PSP = MIPS (Allegrex).
• OS & APIs: Nintendo proprietary vs. Sony proprietary.
• Screen layout: DS dual-screen (one touch); PSP single screen.

There is no emulator, adapter, or hack that enables DS games on PSP hardware. For portable DS play, use a DS/DSi/3DS or PC/mobile emulator (DeSmuME, melonDS, DraStic).