The Irish bowled out Uganda for 155 and Gary Wilson's 61 and 44 from William Porterfield helped Phil Simmons' side reach their target in the 41st over.
Lendl Simmons and William Perkins put on 43 in five overs, Daren Ganga hit a rapid 23 and Denesh Ramdin made 39 from as many balls in Trinidad's 150-9.