Fell was born on 28 March 1855 at his parents' house Sunnyside[a] in Nelson, New Zealand.

Two more siblings were born in New Zealand before the family decided to return to England for better educational opportunities; they left in January 1859.

[5] Walter Fells' brothers Charles and George had returned to permanently live in New Zealand in 1870 and 1871, respectively.

After a variety of assignments, he worked at the Bethnal Green Soldiers' Hospital and gained the rank of major.

[7] In 1910, he moved to the eastern side of Wellington Harbour to an area belonging to Lower Hutt, where he was one of the first residents.

[9] On 26 April 1886 at St Paul's Church in Wellington, Fell married Margaret (Margie) Richmond.

The wedding reception was held at judge Richmond's house and afterwards, the couple left for a honeymoon at Rotorua to visit the various lakes.