Cricket star Watkin has been selected to represent the New Zealand under-22 women's indoor cricket team to compete at the World Cup in Dubai later this year.
Morpeth has already returned from the Oceania Speed Skating championships in Brisbane where he won two silver medals in the 200m time trial and the 3000m in a two-man relay team.
He also brought home two bronze medals in the 5000m points race and 21km half marathon.
Trust Chair and former Olympian Philippa Baker-Hogan said it was great to be able to support athletes in sports the trust had not supported previously.
"This highlights the wide and varied sporting talent we are breeding in Whanganui," she said.
"Trustees are so grateful to Mitre 10 MEGA Wanganui, Leedstown Trust and all our wonderful supporters who make our twice-yearly grants possible."
Sport Whanganui CEO and trustee Danny Jonas said the grants were a great opportunity to profile the city's outstanding young sports achievers as role models for younger children in Whanganui.
"The Trust also fits perfectly in supporting Sport Whanganui's Promising Athlete Programme which helps support identified sporting achievers with other support to assist their sporting performance."
Mitre 10 MEGA Wanganui owner Hayden Gibson his business was committed to giving back to the community.