John Barrow was born in Mumbai, India, on 4 March 1894, the son of Oscar Theodore Barrow and Helen Emma Winifred Barrow (née Reynolds). He joined the Royal Navy as a Cadet on 15 January 1907. He was promoted to Midshipman on 15 September 1911 and appointed to the battleship HMS BELLEROPHON on the same date. He was promoted to Acting Sub Lieutenant on 15 January 1914.

In August 1914 he was appointed to the Submarine Depot Ship HMS MAIDSTONE at Harwich for HMS E3 as Navigating Officer. E3 was lost on 18 October 1914. The submarine had been detailed to patrol off the Island of Borkum and was on the surface when it was sighted by the U-Boat U-27 (Lieutenant Commander Bernhard Wegener). The Commander of U-27 fired his torpedoes and sank E3. It is reported that four of the crew were seen in the water after the submarine sank but the Commander of U-27 was unwilling to close the area to make a rescue as he was concerned that there was another British submarine in the area. When he finally closed the area of the sinking, all four had vanished. As a result, all the crew of HMS E3 died in the sinking.

John Barrow, who was 20 years old when he died, is commemorated on the Portsmouth Naval War Memorial on Panel No. 1.