肌钙蛋白C（英语：Troponin C）是肌钙蛋白复合物的组成部分之一。其结构通常包括四个钙结合EF手结构域，少部分亚型的钙结合结构域会少于四个。肌钙蛋白和肌动蛋白与原肌球蛋白一起组成细肌丝。 It contains an N lobe and a C lobe. The C lobe serves a structural purpose and binds to the N domain of TnI. The C lobe can bind either Ca or Mg. The N lobe, which binds only Ca, is the regulatory lobe and binds to the C domain of TnI after calcium binding.

Troponin C is a part of the troponin complex. It contains four calcium-binding EF hands, although different isoforms may have fewer than four functional calcium-binding subdomains. It is a component of thin filaments (along with actin and tropomyosin). It contains an N lobe and a C lobe. The C lobe serves a structural purpose and binds to the N domain of troponin I (TnI). The C lobe can bind either Ca or Mg. The N lobe, which binds only Ca, is the regulatory lobe and binds to the C domain of troponin I after calcium binding.