SoulGold Legendary Locations

Johto story encounters

• Raikou, Entei, Suicune — roam after the Burned Tower event.
• Lugia — choose the Silver Wing after the Rocket takeover. If you chose Rainbow Wing, speak with the Director after the Elite Four.
• Ho-Oh — choose the Rainbow Wing after the Rocket takeover. Mirror path if you chose Silver Wing.
• Shadow Lugia — south of Johto, Abandoned Rocket Warehouse, Dark Crystal, then the regular Lugia encounter. Title Defense can reset the spawn if Lugia is already caught.
• Celebi — solve all eight Ruins of Alph puzzles, take the GS Ball to Kurt, then the Ilex Forest shrine.

Birds and statics

• Articuno — Snowtop Mountain (Rock Climb).
• Zapdos — top of Olivine Lighthouse after the eighth badge.
• Moltres — Victory Road.
• Galarian Articuno, Zapdos, and Moltres — Route 50 Battle Café, 5 points each.
• Mewtwo — Nameless Dungeon at Kitakami Border after the Elite Four (Rock Climb).
• Mew — after eight badges, defeat Blaine at Olivine port to unlock Faraway Island.

Regis and later

• Regirock — Vajra Desert West (bring Tyranitar).
• Regice — Snowtop Mountain (bring Baxcalibur).
• Registeel — Railway Cave (bring Kommo-o).
• Regigigas — Mt. Silver back room with the three Regis.
• Latias and Latios — Vajra Desert East temple in the postgame.
• Kyogre / Groudon — dive spots after the Darkrai event (south of Route 33 / Route 50).
• Rayquaza — defeat Steven in the Kitakami house as Champion, then Embedded Tower.
• Jirachi — complete the rival story at Mt. Silver.
• Uxie, Mesprit, Azelf — Rock Climb spots on Route 30, Route 47, and Mahogany Town.
• Dialga, Palkia, Giratina — Hoopa plus all Ruins of Alph puzzles, then the Celebi secret room.
• Heatran — depths of Mt. Mortar after Waterfall and Rock Climb.
• Cresselia — after the Mt. Silver rival story, Lake of Rage quest.

The official page continues beyond this summary. Check it before treating any encounter as complete.