A support and control device for circular knitting machines, destined to be mounted in a circular knitting machine equipped with at least one supporting structure, with at least one component-holding unit rotating around a central axis of rotation, and with a plurality of stitch formation components movably associated with the component-holding unit, the device comprising at least one support body provided with: - a mounting portion configured for allowing the device to be mounted to the supporting structure of the circular knitting machine; - a front side directed towards and directly facing said component-holding unit of the knitting machine, the front side being provided with at least one cam for controlling at least a part of said plurality of stitch formation components, said at least one cam defining a guiding path configured for interacting with respective butts for controlling each of the stitch formation components of said at least a part of said plurality of stitch formation components; - a rear side, opposed to said front side and facing the outside of the knitting machine, away from said component-holding unit; wherein a front face of said at least one cam at said front side is without undercuts or holes or hollow surfaces facing said component-holding unit, with the exception of the guiding path defined by said at least one cam; and wherein the device comprises a first side face and a second side face, which are transversal to and structurally connect said front side and said rear side, and wherein the first side face and the second side face are arranged on opposite sides with respect to said at least one cam, in particular with respect to said guiding path; and wherein said at least one cam is defined on a cam body, removably mountable to the support body of the device, so that the guiding path is defined on said front side; said device being characterized in that said cam body comprises a front portion on which said guiding path is defined, and a fastening portion placed laterally to said front portion and provided with fastening means for fastening the cam body to said first side face or second side face of the support body of the device. the device comprising at least one support body provided with: - a mounting portion configured for allowing the device to be mounted to the supporting structure of the circular knitting machine; - a front side directed towards and directly facing said component-holding unit of the knitting machine, the front side being provided with at least one cam for controlling at least a part of said plurality of stitch formation components, said at least one cam defining a guiding path configured for interacting with respective butts for controlling each of the stitch formation components of said at least a part of said plurality of stitch formation components; - a rear side, opposed to said front side and facing the outside of the knitting machine, away from said component-holding unit; - a mounting portion configured for allowing the device to be mounted to the supporting structure of the circular knitting machine; - a front side directed towards and directly facing said component-holding unit of the knitting machine, the front side being provided with at least one cam for controlling at least a part of said plurality of stitch formation components, said at least one cam defining a guiding path configured for interacting with respective butts for controlling each of the stitch formation components of said at least a part of said plurality of stitch formation components; - a rear side, opposed to said front side and facing the outside of the knitting machine, away from said component-holding unit; wherein a front face of said at least one cam at said front side is without undercuts or holes or hollow surfaces facing said component-holding unit, with the exception of the guiding path defined by said at least one cam; and wherein the device comprises a first side face and a second side face, which are transversal to and structurally connect said front side and said rear side, and wherein the first side face and the second side face are arranged on opposite sides with respect to said at least one cam, in particular with respect to said guiding path; and wherein said at least one cam is defined on a cam body, removably mountable to the support body of the device, so that the guiding path is defined on said front side; said device being characterized in that said cam body comprises a front portion on which said guiding path is defined, and a fastening portion placed laterally to said front portion and provided with fastening means for fastening the cam body to said first side face or second side face of the support body of the device.