Eighty-four men and 20 women will contest the titles, which will be decided over 72 holes on the Corstorphine hilltop course.
''This year's event has attracted 25 more entries than we had last year,'' St Clair professional Neil Metcalfe said.
The competitors will get a practice round today when they compete with locals in an am-am competition.
New Zealand Golf has combined the North Island amateur championship with the Charles Tour event at Akarana, which will preclude up to 60 amateurs from competing due to professional entries.
Other leading North Island golfers include Cameron Jones and Jason Gulasekharam (both North Shore), Shiv Sabherwal (Manukau), George Helsby (Royal Auckland) and Matthew Morris (Hamilton).
Ryan Chisnall (Nelson) won the title a year ago but has not ventured South to defend his title this year.
Vaughan McCall (Gore) is one of New Zealand's top golfers who is very familiar with the St Clair course and may be the top South Island contender.
The entry of Canadian Jeffrey Gauf on a handicap of 3.0 adds an international flavour to this year's event.
The field includes 24 Canterbury golfers, while all of the Otago men's team will compete with the exception of James Anstiss, who has taken up a scholarship at Southeastern Louisiana University.
Brent McEwan, the doyen of Otago and St Clair golf, will relish playing at home and he could be the best prospect of the Otago golfers.
Others include Otago No 1 Duncan Croudis, Nick Borren, Mark Brooks and reserve Brandon Hodgson.
Of the 20 women, Momoka Kobori (Rangiora) and Brooke Hamilton (Maungakiekie) are the frontrunners, playing off handicaps of +2.0.
Catherine Bell (Christchurch), daughter of Aorangi evergreen Robbie Bell, and Krystal Hu (Gulf Harbour) are also competing on plus handicaps.
