Ortofon is a Danish manufacturer of phono cartridges, founded on October 9, 1918, by engineers Axel Petersen and Arnold Poulsen. Originally established as the Electrical Phono Film Company to develop synchronized sound-for-film systems, the company rebranded as Ortofon in 1947 and shifted its focus to phonograph cartridge technology. Headquartered in Nakskov, Denmark, Ortofon is the world's largest producer of magnetic cartridges for turntables, manufacturing approximately 500,000 units per year.

Ortofon's product range spans both hi-fi and DJ markets. Their audiophile lines include the popular 2M series of moving magnet cartridges, the budget-friendly OM series (standard equipment on many entry-level turntables), and high-end moving coil designs like the SPU series (in production since 1959), the Cadenza series, and the flagship Anna Diamond. On the DJ side, the Concorde cartridge line — first introduced in 1979 and updated with the MKII generation — is an industry staple, known for its integrated headshell design that provides better visibility for cueing and strong tracking performance. DJ cartridges account for the majority of Ortofon's sales.

Beyond cartridges, Ortofon produces tonearms, step-up transformers, and turntable accessories. The company also operates a precision manufacturing division, Ortofon Microtech, which produces micro-mechanical components for the hearing aid industry. With a distribution network spanning more than 60 importers worldwide and dedicated subsidiaries in the United States and Japan, Ortofon is a cornerstone brand in vinyl playback.

Ortofon has 42 products cataloged on Equipboard, including DJ Accessories and Turntables. Their gear is featured by 11 artists, with the strongest followings in Electronic, Hip Hop, and Pop. Notable users include Derrick May, Fred Falke, and kid606.