Drewitt (Long Reef), won the Golf SA Amateur Classic at the end of April and was second at The Tote Tasmanian Open and third at the Riversdale Cup.
He has recorded six top 10 finishes this year and is second on the Australian Men's Ranking System and will join the squad at Tier 2 level.
Cathleen Santoso joins the National Junior Squad following her victory at the Australian Girls' Amateur Championship in April.
The Lakes Golf Club member joins the Squad after moving into the Top 200 on the World Amateur Rankings. Santoso also had top 10 finishes at both the Aaron Baddeley International and Jack Newton Junior.
National Squad member Julia Boland (Tamworth & Pennant Hills) will travel to Kobe, Japan to compete at the Suntory Ladies Open on the LPGA of Japan Tour from 9-12 June.
The tournament's Honour Roll includes Australia's own Nikki Campbell and current LPGA Tour players Ai Miyazato and Momoko Ueda.
Also in Japan, Western Australia's Oliver Goss and Queensland's Maverick Antcliff will represent Australia at the Japan Amateur from 5-9 July at Miyoshi Golf Club.
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