Call of Cthulhu Miniatures
There have been a number of companies licensed to produced a range of miniatures for the Call of Cthulhu roll-playing game, but there have be a many others ranges which have been licensed from other sources for other Cthulhu Mythos games.
In the 1980s Grenadier produced a range of 25mm miniatures box sets and blister packs for the Call of Cthulhu role-playing game. When they lost the license some of the miniatures was re-package as part of their Nightmares range (back in production by Mirliton).
Games Workshop / Citadel Miniatures
In the mid 1980s Citadel Miniatures produced a range of 25mm Gothic Horror miniatures which was designed to support the Call of Cthulhu license for publishing the Games Workshop editions of the Call of Cthulhu rules and adventures (OOP).
In the late 1980s a German company called Metal Magic which produced the Dunwich Detective range of 25mm miniatures, based on the H.P. Lovecraft's Cthulhu Mythos, not licensed from the Call of Cthulhu role-playing game (back in production from Moonraker Miniatures and EM4 Miniatures).
RAFM are the current licensed manufacture of a line of 28mm Call of Cthulhu miniatures. In 2013 RAFM have started a new range of 32mm miniatures to support the 7th edition Call of Cthulhu RPG.
Black Cat Bases
Black Cat Bases are producing a range of 28mm Cthulhu Mythos miniatures (The Mi-Go are worth a look).
Reaper Miniatures have produced a few Mythos monster's in their miniatures range.
Frenris Games produce some 28mm Cthulhu Mythos Miniatures and Scenery.
Manufacture of 28mm Mythos miniatures, no longer in busness. A number of the miniature lines have been sold to other manufactures (including C P Models and Harwood Hobbies).
C-P Models are now producing a range of 28mm Cthulhu Mythos miniatures, part off their Night Terrors range.
Impact! Miniatures produce a range of Fantasy Football miniatures including a team of "Cthulhu/Necromicon" miniatures.
Green Eyes Games
Green Eye Games published a game in 2015 called Cthulhu Wars with miniatures which was modelled by Fenris Games (some of which are available direct from Fenris Games).
Modiphius Entertainment produce a range of Achtung! Cthulhu 28mm scale mythos miniatures including "Mythos Monster" miniatures, Nazi Villains, Allied Investigators and more.
Avolak Castings are producing a range of Cthulhu Mythos 28mm miniatures (also a game is due to be published).
Scibor Miniatures have produced a small range of Cthulhu Mythos 28mm miniatures.
Khurasan Miniatures makes a range of 15mm "1930s Eldritch Horror" miniatures. Some of the large models could be used with 28mm miniatures.
Wizkids makes a collectable miniature game called HorrorClix which is supported by a miniature expansion set called; "The Great Cthulhu Collectors Set" (OOP).
Harwood Hobbies are producing a range of 28mm "Lovecraft Circle" miniatures.
Blind Beggar Miniatures
Blind Begger Miniatures is a independent 28mm miniature manufacture. Makes some excellent Deep Ones Hybrids.
Crucible Crush are producing a number of Cthulhu miniatures sets for their Cthulhu 28 range.
Midlam Miniatures have a number interesting miniatures which could be used for horror games including the "Cult of the Kraken Lord" range.
Eureka Miniatures have a line of Movie Monster miniatures which includes a range of Fishermen (Hybrid Deep Ones).
North Star have produced some intresting miniatures for the Dracula America game (inc. Church of Dagon minatures) and some Deep Ones miniatures (North Star Horror).
Part of The Propworkshop makes fantasy and SF miniatures, but the Bucca from the The Woods range look like Deep Ones.
Over the last few years a number Crowdfunding projects have been published with a range Cthulhu Mythos miniatures, including the following which are only avaliable as a Kickstarter;