Since I'm constantly asked about the locations of all Clue scroll npcs, I decided to post a list of all the npcs (the ones I recalled when making this).
Bear in mind this is not a guide, just a list of people in their locations (I can also describe their locations in more detail if needed).
I encourage our fellow contributors to actually make a guide based on this list.
If there's something missing, feel free to let me know by posting below
For a quick search press CTRL + F and type in that person's name.Al-Kharid: Gertrude (near teleport location; also near Varrock), Jaraah (teleport location; also at Duel Arena), Meteora (north of teleport location; also at Falador and Edgeville)
Ancient cave: Shenven (in a room before Ancient Gladiators etc)
Ardougne: Councillor Halgrive (go west from Ardougne market/teleport location until the castle bridge, he's in front of one of the houses), Aubury (also in Port Sarim and Varrock)
Barbarian village: Thomy, Hunding/Hundig, Fish Monger (also in Rellekka
Burthorpe: Ghommal (in front of Warrior's guild, currently misspelled Ghommel), King Gjuki Sorvott IV (castle's ground floor)
Camelot: King Arthur (castle's ground floor)
Canifis: Barker
Castle Wars lobby: Lanthus
Catherby: Harry (fishing store)
Crafting guild: Master Crafter
Draynor village: Brian, Dark mage (also in Edgeville), Charlie the cook, Farmer Fromund (field east of Charlie the cook)
Duel Arena: Jaraah (also at Al-kharid)
Edgeville: Meteora (also at Falador and Al-Kharid), Dark Mage (also at Draynor Village), Brother Jered (monastery; also in Varrock castle), Vannaka, Wilderness guide
Falador: Flynn (pickaxe store), Robe Store owner (south of western Falador bank), Meteora (southern part of Falador; also in Al-Kharid and Edgeville), Sir Tiffy Cashien
Grand Exchange: Matt (under a tree south-eastern part of GE), Bolkoy
Heroes' guild (south of Burthorpe)
: Achiettes
Karamja store: Pirate Jackie the Fruit
Lumbridge: Mazchna, Bob (also in Port Sarim)
Obsidian Caves: TzHaar-Mej-Kah (near bank/Jad minigame entrance), TzHaar-Hur-Lek (minigame reward shop), TzHaar-Mej-Roh (near minigame rewards guy)
Port Sarim: Bob (also in Lumbridge), Gem merchant, Gerrant, Brother Brace (in small chapel south-west Port Sarim), Aubury (also in Ardougne and Varrock)
Rellekka: Freygerd (one of the houses east from the pub), Sassilik (Relleka market), Jarvald (in front of the viking ship that takes you to Waterbirth; also at Waterbirth island), Fish Monger (also in Barbarian village)
Rimmington: Hickton, Grum, Ilfeen (house near whirlpool), Simon Templeton (in front of whirlpool), Sigbert the Adventurer (crater)
Taverley: Sanfew
Varrock: Brother Jered (Varrock castle 1st floor; also at Edgeville monastery)Gertrude (in a house south-west from Varrock big bank, outside of city; also at Al-kharid), Aubury (also in Ardougne and Port Sarim)
Waterbirth island: Jarvald (also at Relleka)
Brother Kojo:
Barbarian agility course (teleport available via Galahad in Barbarian village),
Clocktower (building south-west of Ardougne)
Spirit: In front of both
Revenant cave entrances