We have almost no biographical information about Estelmo, but as esquire to Isildur's eldest son and heir, he presumably dwelt in Minas Ithil, which was Isildur's seat in Gondor. It is unclear what happened to Estelmo after the Disaster of the Gladden Fields; he may have settled in the North (where his master's younger brother was now formally High King), or he may have returned to dwell in Gondor.

The estel- in Estelmo's name is well established as meaning 'hope'. The -mo element is a masculine name-ending, so in full Estelmo might be taken as something like 'Man of hope'. However -mo is typically taken as 'agental', representing a more active aspect. In this case, the activity in question is ambiguous, but the name might conceivably be interpreted as something like 'bringer of hope'.