An elastic wave device includes a first piezoelectric substrate including a first principal surface and a second principal surface, a second piezoelectric substrate including a first principal surface and a second principal surface and with a greater thickness than that of the first piezoelectric substrate, and ground terminals located on the second principal surface of the first piezoelectric substrate. The first principal surface of the first piezoelectric substrate and the first principal surface of the second piezoelectric substrate are joined to face each other. On the first principal surface of the first piezoelectric substrate, a first elastic wave filter is located. On the first principal surface of the second piezoelectric substrate, a second elastic wave filter is located. The out-of-band attenuation of the first elastic wave filter is greater than the out-of-band attenuation of the second elastic wave filter.