Sentret locations — where to catch

In Kitakami (Scarlet & Violet – The Teal Mask)

• Apple Hills — Walk
• Kitakami Road — Walk
• Mossfell Confluence — Walk
• Reveler's Road — Walk
• Wistful Fields — Walk

In Sinnoh (Diamond, Pearl & Platinum)

• Route 202 — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Johto Safari Zone — Walk
• Route 1 — Walk
• Route 29 — Walk

In Sevii Islands (FireRed & LeafGreen)

• Canyon Entrance — Walk
• Five Isle Meadow — Walk
• Water Path — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Route 1 — Walk
• Route 29 — Walk
• Route 43 — Walk

Other games (3)

• Brilliant Diamond / Shining Pearl (Gen 8): Route 202
• X / Y (Gen 6): Kalos Route 6
• Black / White (Gen 5): Route 7

Sentret — full Pokédex entry