Is entropy a function of temperature for ideal gases?

Yes, entropy is a function of temperature for ideal gases.

The change of entropy of a substance is given by the relationship ΔS = ∫ dQre/T

And dQ = dU + P dV

For an ideal gas both U and V are a function of de T.

=> dS = [dU]/T + P[dV]/T,

dU = Cv dT

PdV = nRT/V

=> dS = Cv [dT] / T + nR[dV] / V

There you can see that the change of entropy, dS, is a function of T.

Yes, entropy is a function of temperature for ideal gases. Changes in temperature affect the entropy of ideal gases.