Koh-i-Noor Hardtmuth a.s. is a Czech manufacturing company of stationery products, based in České Budějovice.

With four factories in its country of origin (České Budějovice, Městec Králové, Broumov, and Milevsko) and one in Bulgaria, the company manufactures and sells a wide range of writing implements, art materials, and office products, exporting them to more than 90 countries worldwide.

In 1848, Joseph's sons, Karl and Ludwig, took over the family business, and the production was relocated to the Bohemian city of Budweis (České Budějovice, within the current Czech Republic).

The products were given awards in many world exhibitions, including in 1855 in New York City, 1856, 1900 and 1925 in Paris, 1862 in London, 1882 in Vienna and 1905 in Milan.

Koh-i-Noor was a partner in making Jiří Barta's 2009 animated feature Toys In the Attic, and its pencils appear frequently throughout the film.