Conrad Heinrich Küchler (c. 1740 – 1810), surname usually rendered in English as Kuchler, was a German engraver who from 1793 until his death worked as a designer of coinage and medals for the manufacturer and mint owner Matthew Boulton.
Küchler was born in Flanders around 1740. He first came to England in March 1793, where he was employed as an engraver at the Soho Mint, owned by the notable manufacturer Matthew Boulton. He was Boulton's sole artist for designing and die-cutting, and produced the designs for various coins, medals and tokens, including the copper "cartwheel" pennies and twopences, and medals depicting the Battle of Trafalgar, Louis XVI and Marie Antoinette. He later left the Mint, but continued to be employed by Boulton's firm in London until his death. Küchler died in Handsworth in 1810.
Three of his effigies of George III can be found on English coins:
- an earlier laureate draped bust with a fuller figure of the monarch (1797, on the famous Cartwheel pennies of the Soho Mint)
- a slightly different one depicting a smiling monarch (on some emergency money of 1804 by the Soho Mint)
- and a later one with a visibly thinner monarch and a slightly different arrangement of the drapes and hair (on 1806 "Fourth Issue" copper coinage of the Royal Mint)