The year 1909 in radio contained a number of significant events.

• 18 March – Einar Dessau uses a shortwave radio transmitter in Denmark.^[1]
• Charles Herrold begins experimental voice transmissions in San Jose. KCBS (AM) (formerly KQW) has considered these transmissions to be the beginning of its broadcast history.^[2]

• 6 February – René Cutforth, English broadcaster (died 1984)
• 3 March – Al Read, English radio comedian and sausage manufacturer (died 1987)^[3]
• 24 March – Tommy Trinder, English radio, stage and screen comedian (died 1989)
• 6 May – Loyd Sigmon, American amateur radio broadcaster (died 2004)^[4]
• 1 December – Frank Gillard, English radio reporter and executive (died 1998)^[5]
• 23 December – Maurice Denham, English character actor (died 2002)