Recently, Luo introduced Fourier expansions of Apostol-Bernoulli, Apostol-Euler and Genocchi polynomials and investigated some interesting identities and properties of these polynomials by using Fourier series. In this paper, we consider three types of functions given by sums of products of Genocchi functions and derive their Fourier series expansions. In addition, we will express each of them in terms of Bernoulli functions.