"It's a bit of a shock but it is a tremendous honour, I suppose," he said.
"And a lot of people have helped me right through. In 50 years of judging I've had a hell of a lot of people help me. It was a big shock when the letter came."
Equestrian Sports New Zealand chief executive Jim Ellis has described Morris as one of the most respected officials.
"Peter has officiated in the sport at the highest level for more than 40 years, is admired by riders, officials and other volunteers alike for his calm approach and perhaps the best understanding of the rules of our sort of anybody," he said.
"Peter is renowned for his quietly spoken and considered approach, his calmness under pressure, his willingness to share his knowledge, his unfailingly high standards and infectious humour.
"Above all, he has throughout his judging career been a friend to generations of riders, helping them to understand, and occasionally to comply, with the rules."