Frank Wild was born in Skelton-in-Cleveland, North Riding of Yorkshire, the eldest of eight sons and three daughters born to schoolteacher Benjamin Wild and his seamstress wife Mary (née Cook). The family came from Skelton close to Marton, birthplace of Captain James Cook, to whom the family claimed ancestry through Mrs Wild. Her father was Robert Cook, who claimed to be a grandson of the great explorer. By 1875 the Wild family had moved from Skelton to Stickford in Lincolnshire, and in late 1880 moved again to Wheldrake near York.
Wild's family next moved to the village of Eversholt in Bedfordshire. Here his father was appointed clerk of the Eversholt Parochial Charity at Woburn. Frank Wild was educated at Bedford. He joined the Merchant Navy in 1889 at the age of 16, receiving his early training in sail in the clipper ship Sobraon. In the Merchant Navy he rose to the rank of second officer. In 1900, aged 26, he joined the Royal Navy. The 1901 census shows that at that time he was serving as an Able seaman aged 27 on HMS Edinburgh, anchored in Sheerness Harbour.