Manectric locations — where to catch

In Lumiose City (Legends: Z-A)

• Lysandre Labs — Walk, Static Encounter
• Magenta Sector 5 — Static Encounter
• Wild Zone 9 — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Johto Safari Zone — Walk

In Hoenn (Ruby, Sapphire & Emerald)

• Route 118 — Walk

Other games (6)

• Sword / Shield — The Isle of Armor (Gen 8): Max Lair
• Sword / Shield (Gen 8): Axew's Eye, Giant's Cap, Giant's Seat, Motostoke Riverbank, Rolling Fields
• Ultra Sun / Ultra Moon (Gen 7): Alola Route 12
• X / Y (Gen 6): Friend Safari
• Black 2 / White 2 (Gen 5): Hidden Grotto, Unova Route 3
• XD (Gen 3): Citadark Isle

Manectric — full Pokédex entry