甚低频（VLF, Very low frequency）是指频带由3KHz到30 KHz的无线电波。

VLF多数用作潜艇通信、无线心跳频率检测器及地球物理学研究等。另外对于雪崩时的人命及财产搜索，VLF亦起了一定的作用。

无线电波名
英文缩写
频率下限
频率上限
最大波长
最小波长

极低频
ELF
3 Hz
30 Hz
100000 km
10000 km

超低频
SLF
30 Hz
300 Hz
10000 km
1000 km

特低频
ULF
300 Hz
3 kHz
1000 km
100 km

甚低频
VLF
3 kHz
30 kHz
100 km
10 km

Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3 kHz to 30 kHz and wavelengths from 10 to 100 kilometres. Due to its limited bandwidth, audio (voice) transmission is highly impractical, and therefore, only low data rate coded signals are used. The VLF band is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication. Since VLF waves penetrate about 40 meters into saltwater, they are used for military communication with submarines. The band is also known as the myriametre band or myriametre wave as the wavelengths range from one to ten myriametres (an obsolete metric unit equal to 10 kilometres).