A circuit device includes a phase comparator that performs phase comparison between an input signal based on an oscillation signal and a reference signal, a processor that performs a signal process on frequency control data based on a result of the phase comparison, and an oscillation signal generation circuit that generates the oscillation signal having an oscillation frequency which is set on the basis of frequency control data having undergone the signal process. The phase comparator includes a counter that performs a count operation by using the input signal, and performs the phase comparison by comparing a count value in the counter inn (where n is an integer of 2 or more) cycles of the reference signal with an expected value of the count value in integers.