LunaStone is a Danish boutique effects pedal company based in Copenhagen, founded by engineer and guitarist Steen Grøntved. The brand traces back to 2011, when Grøntved and friend Morten Lunau began jamming and experimenting with pedal clones together — the name combines "Luna" from Lunau's surname and "Stone" from the Danish translation of Steen. Lunau later stepped away, and Grøntved continued developing the circuits on his own while completing an electronics thesis at the Technical University of Denmark.

The company is best known for its TrueOverDrive™ approach, which avoids the diode clipping used in most overdrive pedals in favor of cascaded gain stages designed to respond more like a tube amp being pushed hard. Core models include the TrueOverDrive 1 and TrueOverDrive 2, the Wise Guy, the Big Fella, the Three Stage Rocket (with a MIDI variant), Smooth Drive 1, Blue Drive 1, Red Fuzz 1, Distortion 1, Boost 18, Dynamic Delay, and the Deep Metal high-gain pedal.

LunaStone pedals use true-bypass switching and emphasize transparency and sustain, aiming to preserve the character of the player's amp and guitar through the drive. The brand occupies a small-batch, engineer-driven niche within the European boutique pedal scene.

Lunastone has 10 products cataloged on Equipboard, including Overdrive Effects Pedals, Boost Effects Pedals, and Distortion Effects Pedals. Their gear is featured by 2 artists, with the strongest followings in Rock and Metal. Notable users include Miyako and Soren Andersen.