Castledine Electronics is a small pedal-building operation founded in 2002 by Stuart Castledine in the United Kingdom. The company specializes in hand-built, made-to-order guitar effects that reproduce or reinterpret classic vintage circuits, with a focus on fuzz, wah, and modulation. Castledine is often grouped with the New Wave of British Pedal Makers (NWoBPM) that emerged around the D*A*M forums, and Stuart has a reputation as one of the UK's more meticulous researchers of vintage effect circuits.

The catalog leans heavily on faithful recreations of late-1960s and early-1970s designs. Notable builds include the V2 Fuzz, based on the violet Ram's Head Big Muff, the Magical Mystery Box (a Vox-style tone box aimed at Beatles-era sounds), Tone Bender variants, Fuzz Face-style circuits using vintage transistors such as the BC183L, Uni-Vibe-style modulation units, and exacting clones of vintage wah-wah pedals — the latter reflected in the operation's longtime web address, wah-wah.co.uk. Castledine has also collaborated with David Main of D*A*M on co-built pedals for the Macaris Coloursound reissue line.

Because pedals are built to order in small quantities, distribution is largely direct through the company's own site and Reverb, with limited dealer presence through boutique shops such as Deluxe Guitars in Australia.

Castledine Electronics has 4 products cataloged on Equipboard, including Univibe & Rotary Effects Pedals, Distortion Effects Pedals, and Overdrive Effects Pedals.