A universal trigonometric function generator which is selectively programmable by pin-strapping to generate any of the standard trigonometric functions (sine, cosine, tangent, cotangent, secant and cosecant). The circuit includes two identical sine-function generating networks each of which produces an output signal proportional to the sine of a corresponding angle input. These networks are so interrelated that the composite output signal is proportional to the angle input of one network and inversely proportional to the angle input of the other network, producing an output ##EQU1## where A is a controllable amplitude, .theta..sub.1 -.theta..sub.2 is the angle input to one network, and .phi..sub.1 -.phi..sub.2 is the angle input to the other network. By selectively connecting the input terminals for .theta..sub.1, .theta..sub.2, .phi..sub.1, .phi..sub.2 to an angle control signal and reference voltages corresponding to 0.degree. and 90.degree., any one of the standard trigonometric functions can be generated.