Moon spent the past few weeks on trial at the Scottish club in an attempt to secure a European deal.
However, a local publication, Edinburghlive, reports that Moon didn't do enough to convince manager Paul Heckingbottom.
The left-footed striker played in three friendly matches for Hibernian during his trial period.
He found the back of the net in Hibernian's 3-2 loss to Arbroath after coming on as a second-half substitute in his first match.
Moon also featured in the Scottish club's 3-1 win over Dunfermline before playing his final match for the East End Park-based outfit in the 4-3 win at Carlisle United earlier this week.
Despite his efforts, Hibernian still didn't see the need to offer the 22-year-old a deal and now Moon has to continue looking for a new home elsewhere.
The Pietermaritzburg-born marksman is expected to return to South Africa this week.
In June, Moon told Goal he was still weighing up his options - this was soon after leaving Kaizer Chiefs whom he spent three seasons between 2016 and 2019.
Maritzburg United have not ruled out the possibility of re-signing their former striker, but as things stand, no talks have been held between the two parties.