This page lists every Mega Stone in Pokémon Radical Red, along with details on where to find them and a screenshot of each Mega Stone’s exact location.
If you need more help then you can click any Mega Stone’s name in the table below to read a full step-by-step tutorial on exactly where to get the stone.
Mega Stone Location Screenshot Abomasite In the Seafoam Islands B2F, in the South part of the room. 
Absolite On Route 17, in between two ponds and next to a sign. 
Aerodactylite From the Pewter City Gym, after defeating Brock in a rematch. 
Aggronite From the Cinnabar Island Pokémon Lab, given by Jasmine after beating her. 
Alakazite Given by the girl on the rooftop of the Celadon City Department Store. 
Alcremite Given by a woman in Saffron City after giving her ingredients for a cake. 
Altarianite On Route 18, in the class directly under the connector leading to Bicycle Road. 
Ampharosite Found in the North-East corner of the Power Plant. 
Applite Given by the two ladies in the Celadon City Hotel after you acquire the Mega Ring and beat them in a battle. 
Audinite Found in the Silph Co. 6F, at the South-West part of the floor. 
Banettite Found in the Cinnabar Island Pokémon Mansion B1F’s South-West side. 
Beedrillite In a small enclosed area located in the Safari Zone’s Area 2. 
Blastoisinite Upper floor of the lower gate connector on Route 16. Speak with the scientist NPC and show him a Blastoise. 
Blazikenite Given by May after defeating her outside of the Cinnabar Island Pokémon Mansion. 
Butterfrite In the South-West section of Viridian Forest, at the end of the path blocked by smashable rocks. 
Cameruptite In the Pokémon Mansion’s first floor, the bottom-right corner of the area you reach by falling. 
Centiskite Given by Ace Trainer Cole after getting the Mega Ring and defeating him on Route 8. 
Charizardite X Upper floor of the lower gate connector on Route 16. Speak with the scientist NPC and show him a Charizard. Replaced with the Charizardite Y in hardcore mode. 
Charizardite Y In the Cinnabar Island Gym, given by Blake after defeating him and showing him a Pokemon with 150 EVs in special attack. Replaced with the Charizardite X in hardcore mode. 
Coalossite In the Rock Tunnel’s 1F, behind some smashable rocks. 
Copperajite On a small island directly South of the Vermillion City Gym. Requires the HM Surf. 
Diancite In the Cerulean Cave 2F, in the North-East part of the room. 
Drednawite Found on Route 19, on a small island directly South of Fuchsia City. 
Duraludonite From the Viridian City Gym, after defeating Clair. 
Galladite From the Saffron City Dojo, given by Chuck after defeating him then showing him a Pokémon with 150 EVs in Attack. 
Garbodorite Found in Silph Co. 4F, behind a door to the West that requires a Card Key to open. 
Garchompite In the Cerulean Cave B1F, in the top-right corner of the room. 
Gardevoirite In the Saffron City Gym, after defeating Sabrina and showing her a Pokémon with 31 IVs in all stats. 
Gengarite From Mr. Fuji’s house, given by Morty after defeating him then showing him a Pokémon with max happiness. 
Glalitite Given by Pryce after defeating him on Route 20, outside of the Seafoam Islands cave entrance. 
Gyaradosite From the Cerulean City Gym, after defeating Misty in a rematch. 
Heracronite In the Safari Zone Area 1, next to a Rest House. 
Houndoominite Given by Archer after defeating him in the Cerulean Cave. 
Kangaskhanite Found in Silph Co. 7F, in the bottom-left part of the floor. 
Kinglerite On a small island on Route 21, east of an NPC who’s swimming in circles. 
Laprasite Found in the Seafoam Island’s B1F, in the North-East part of the floor. 
Latiasite Given by a scientist in the Cinnabar Island Pokémon Lab after showing him a Latias. 
Latiosite Given by a scientist in the Cinnabar Island Pokémon Lab after showing him a Latios. 
Lopunnite In the Safari Zone’s Area 3, at the very South of the area below a platform. 
Lucarionite West of the Celadon City Pokémon Center, given by the NPC standing next to a Lucario when speaking to him while having a Lucario companion. 
Machampite Given by the Dumbass Jojo fan after defeating him in the Power Plant. 
Manectite From the Vermilion City Gym, after defeating Lt. Surge in a rematch. 
Mawilite Given by Ariana after defeating her in the Cerulean Cave. 
Medichamite On a small island on Route 20, East of a swimmer NPC. 
Metagrossite Outside of the Indigo Plateau after defeating the Dumbass Creator. 
Mewtwonite X Given by Red at Treasure Beach after defeating him. 
Mewtwonite Y Given by Giovanni after defeating him in the Cerulean Cave. 
Orbeetlite On Route 2, right next to Diglett’s Cave entrance behind a smashable rock. 
Pidgeotite In the Safari Zone’s Area 2, on the North side of the area. 
Pinsirite In the bottom-left corner of Route 6, behind a fence, accessible by destroying a smashable rock. 
Sablenite Found in Lavender Town’s Pokémon Tower on the 3rd floor, on the North side of the room. 
Salamencite Given by Lance after defeating Giovanni in Cerulean Cave. 
Sandacondite Given by Ace Trainer Haley after defeating her on Route 15. 
Sceptilite Given by Brendan after defeating him on Route 23. 
Scizorite Found on Route 22, on the other side of a pond. 
Sharpedonite Given by the fisherman inside the house on Route 12 after speaking with him while having a Sharpedo follower. 
Slowbronite On a small island on Route 12, directly South of the sleeping Snorlax. 
Snorlaxite Found on Route 23, directly to the right after the Volcano Badge checkpoint. 
Steelixite From the Cinnabar Island Pokémon Lab, given by Jasmine after defeating her then showing her a Pokémon with 150 EVs in Defense. 
Swampertite Given by the Dumbass Kid in Saffron City after defeating him and speaking to him with a Swampert follower. 
Toxtricitite From the Fuchsia City Gym, after defeating Koga and showing him a Pokémon with 150 EVs in speed. 
Tyranitarite On a small island on Route 24, directly West of the Nugget Bridge. 
Venusaurite Upper floor of the lower gate connector on Route 16. Speak with the scientist NPC and show him a Venusaur. 
