The 70-centimeter amateur radio band is a portion of the UHF radio spectrum. This band is used by amateurs engaged in emergency communications where portable and mobile radios are frequently used. Many such radios have dual-band capabilities, operating on both the 70-centimeter and 2-meter bands.

The band allocation vary regionally. In the United States,Australia and Trinidad and Tobago the band ranges from 420 to 450 MHz with some geographical limitations; in Canada, the band is only 430–450 MHz; in the UK, amateurs are allocated 430–440 MHz. By international treaty between the US and Canada, operation in the portion of the band from 420 to 430 MHz is prohibited north of Line A, which runs just south of the Canadian border from Washington state to Maine, and east of Line C, which runs from northeast to southeast Alaska.

70-centimeter propagation characteristics lie midway between 2-meter and 33-centimeter (~900 MHz) bands. As frequency increases, building penetration improves.^{[citation needed]} However, smaller obstacles may also block or reflect the signal. Higher frequencies also present a lower noise floor, making it easier to overcome both natural and artificial interference, especially prevalent in urban environments.