Stephen Baine, who runs St. Colman's Primary School in Lambeg, County Antrim, sent the letter to pupils on Thursday to explain school closures.
In his letter, Mr. Baine used the "rootin', tootin' cowboy" Woody, the film's protagonist, to help explain to students how to cope with social distancing and help at home.
Stephen Baine's letter to students at St. Colman's Primary School in Lambeg (Stephen Baine)
"I remember when Woody, Buzz, Rex and the others had to stay apart for a while until a problem was solved when they could all come back together," the letter read.
Mr. Baine expressed concern that children were being left out of the conversation and were not being briefed about the ongoing pandemic.
"Over the past number of weeks we have been writing letter after letter to parents informing them of the school closure procedure," Mr. Baine told the PA news agency.
"I wanted to make sure children understood in their terms what a school closure meant."
Stephen Baine, who sent a 'Toy Story'-themed letter to his students during to explain the situation, talks to a student (Stephen Baine)
Mr. Baine said that the Pixar classic was one of his favorite films, saying:
"I absolutely adore it."
He added that the movie was a great way to :use characters that children are familiar with" to help communicate a clear message during the pandemic.
"Just like the end of the movie it won't be too long until we are all back together as one big group of friends ready to learn, play and have fun together," the letter read.
The principal signed off his letter as "Mr. Baine (Sheriff Woody)" having written that he would "miss you guys to 'infinity and beyond'!"