In the early years, the club grounds moved around the district before settling at the current location behind the Wrights Bush Hall in 1968.
More than 250 people have registered so far with former members coming from all over the country, and even some from overseas.
The club's only All Black was Leicester Rutledge.
The rugged loose forward debuted in 1978 and played 31 games, including 13 tests.
Rutledge played 113 games for Southland before going on to coach and manage the side and is a Southland Rugby life member.
Rutledge is the chairman of the Wrights Bush centennial organising committee.
Also on the committee are Neil Winter, Evan Patterson, Stacey Stuart, Paul Nicholson, Kevin Joyce, Deon Houston, Tamai Puki, Rachel Barret and Graham Marshall.
Another notable Wrights Bush man to have success on the national stage is Graham Cooney, who was a board member of the New Zealand Rugby Union for six years from 2010.
Former club player Keith Brown has been an international referee in the professional era.
John Ellis played 15 games for Southland at first five-eighth in the mid-1970s.
David Hall played 108 games for Southland at hooker and loose forward. Hall also made Highlanders, Hurricanes and Crusaders squads.
Nick Barrett is another former club junior to go on to play professionally for Southland, Auckland, the Crusaders, the Chiefs and New Zealand Maori.
Hall was a vital cog in the revival of Wrights Bush in 2010 after 15 years of not fielding a senior team.
The current senior team is an amalgamation of players from Wrights Bush and neighbour Central Pirates and plays under the Bush Pirates banner in Southland's division two competition.
Schoolboy rugby starts at 10.30am today.
The main game between Bush Pirates and Drummond Limehills Star kicks off at 2pm.
The centennial celebrations move on to the formal dinner at the Working Man's Club in Invercargill at 7pm.
-By John Langford