An electrocardiogram (ECG) sensor includes a motion artifact detector configured to detect a motion artifact component from a first channel signal of a first channel and a second channel signal of a second channel using a channel offset coefficient. The channel offset coefficient indicates a difference between the first channel signal and the second channel signal. The ECG sensor includes an ECG filter configured to generate an ECG signal by performing a least mean square (LMS) filtering operation on the first channel signal to remove the motion artifact component.