Can You Play GTA IV on Xbox One? No.

Grand Theft Auto IV is not backward compatible on Xbox One or Series X|S.

Why

• Licensing / Middleware: Uses Games for Windows Live (GFWL) on PC, custom middleware on 360. Re-licensing music, physics (Euphoria), and engine for emulator wrapper deemed not cost-effective.
• Technical Complexity: RAGE engine on 360 (PowerPC) doesn't translate cleanly to x86 BC layer compared to simpler titles.
• Rockstar Focus: Resources directed to GTA V / Online / RDR2 / next-gen.

How to Play GTA IV Today

• Xbox 360 (Disc/Digital): Native. Digital delisted but works if owned.
• PC (Steam / Rockstar Launcher / Epic): Complete Edition (includes EFLC). Mods fix GFWL, improve graphics (ENB, IVPack, VisualIV). Best version.
• PlayStation 3: Native.
• Cloud (GeForce NOW): Stream PC version from library.

GTA V is on Xbox One/Series (enhanced). GTA IV is not.