An oscillator includes: a resonator element; a circuit element configured to output a clock signal; and a container accommodating the resonator element and the circuit element and including a substrate having a first surface. The substrate includes a first electrode provided on the first surface and electrically coupled to the resonator element, a second electrode electrically coupled to the resonator element, and an output electrode configured to output the clock signal. The first electrode and the second electrode are disposed side by side in a first direction. The output electrode is disposed adjacent to the first electrode in a second direction orthogonal to the first direction. When an end portion of the first electrode on a side close to the second electrode is defined as a first end portion, the output electrode includes a first region disposed closer to the second electrode side than the first end portion in the first direction.