Houndoom locations — where to catch

In Lumiose City (Legends: Z-A)

• Lysandre Labs — Walk
• Wild Zone 6 — Walk, Static Encounter

In Paldea (Scarlet & Violet)

• East Province (Area Three) — Walk
• North Province (Area Two) — Walk
• South Province (Area Six) — Static Encounter

In Kitakami (Scarlet & Violet – The Teal Mask)

• Fellhorn Gorge — Walk
• Kitakami Wilds — Walk
• Oni Mountain — Walk
• Paradise Barrens — Walk
• Timeless Woods — Walk
• Wistful Fields — Walk

In Sinnoh (Diamond, Pearl & Platinum)

• Route 214 — Walk
• Route 215 — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Johto Safari Zone — Walk

Other games (3)

• Brilliant Diamond / Shining Pearl (Gen 8): Route 214, Route 215
• Ultra Sun / Ultra Moon (Gen 7): Alola Route 12
• Colosseum (Gen 3): Realgam Tower

Houndoom — full Pokédex entry