A class in C++ is a user defined type or data structure declared with keyword class that has data and functions (also called methods) as its members whose access is governed by the three access specifiers private, protected or public (by default access to members of a class is private). A class (declared with keyword class) in C++ differs from a structure (declared with keyword struct) as by default, members are private in a class while they are public in a structure. The private members are not accessible outside the class; they can be accessed only through methods of the class. The public members form an interface to the class and are accessible outside the class. Instances of these data types are known as objects and can contain  member variables, constants, member functions, and overloaded operators defined by the programmer.

C class may refer to:

• Mercedes-Benz C-Class, luxury passenger vehicle
• c-Class, a type of server computer by BladeSystem (HP)
• C-class Melbourne tram, the designation given to the type of Citadis trams used in Melbourne
• Victorian Railways C class, locomotives
• NZR C class (1873), locomotives
• NZR C class (1930), locomotives
• SECR C class, a class of 0-6-0 steam locomotive from the South Eastern and Chatham Railway.
• CIE 201 Class (1956), locomotives used in Ireland
• C-class destroyer (disambiguation), multiple destroyers
• C-class submarine (disambiguation), multiple submarines
• C-class cruiser, Royal Navy light cruisers built just before the First World War
• C-class, a European Vehicle size class, a small family car