Cylinder for an actuator (11), in which said cylinder (10) comprises at least a liner (13) of a tubular shape developing along a longitudinal axis (X), a head portion (14) and a bottom portion (15), each disposed at one of the ends of the liner (13), and longitudinal tie rods (21) connected, externally to the liner (13), both to the head portion (14) and to the bottom portion (15); the longitudinal tie rods (21) are distanced with respect to each other on the circumference of the liner (13), they are made of a composite material formed by reinforcement fibers located in a matrix of binder material and wound between the head portion (14) and the bottom portion (15) according to a predominant orientation substantially parallel to said longitudinal axis (X), and have a continuous annular shape defined by two longitudinal branches (21a) connected by two opposite connection portions (21b, 21c).