Istanbul Agop is a Turkish cymbal manufacturer rooted in a tradition that stretches back to the Ottoman Empire. The company was founded in 1980 by master cymbalsmith Agop Tomurcuk, who had been crafting cymbals by hand since the age of nine. Partnering with Mehmet Tamdeğer, they established the original Istanbul Cymbals brand in a small Bakırköy workshop. After Agop's death in 1996, the company split: his sons Sarkis and Arman Tomurcuk formed Istanbul Agop (operating as Istanbul Zilciler), while Tamdeğer continued under the Istanbul Mehmet name. The company is headquartered in Istanbul, Turkey, with a US office in Los Angeles.

Istanbul Agop produces entirely hand-hammered cymbals using proprietary bronze alloy formulas. Their catalog spans a wide range of series, from the warm, fully lathed Traditional line to the modern, versatile XIST series. The company is well known for its artist signature models, including the Mel Lewis, OM (Cindy Blackman Santana), Epoch (Lenny White), Sterling (Aaron Sterling), and Idris Muhammad lines. Other offerings include the dark, complex Custom Turk and Sultan series, the entry-level MS-X student cymbals, and a dedicated Band & Orchestra line.

The brand's early endorsers included jazz legends Mel Lewis, Elvin Jones, Tony Williams, Art Blakey, and Jack DeJohnette. The roster has since expanded to include drummers across genres, such as Cindy Blackman Santana, Aaron Sterling, Lenny White, Yussef Dayes, Bryan Devendorf (The National), Joey Waronker, and Dave Turncrantz (Russian Circles), along with members of The Smashing Pumpkins, Paramore, The Killers, and Arcade Fire.

Istanbul has 700 products cataloged on Equipboard, including Ride Cymbals, Crash Cymbals, and Hi-hat Cymbals. Their gear is featured by 63 artists, with the strongest followings in Rock, Pop, and Jazz. Notable users include Carter McLean, II, and Vinny Appice. Most Istanbul products fall in the mid-tier range — professional-grade without flagship pricing.