Aarush Anand, a pupil at Nottingham High School, wrote the letter on Wednesday as part of an exercise to get students into the festive spirit and improve letter writing.
In the note the year three pupil said: "The only thing I want for Christmas is peace, like in Syria."
Aarush's teacher said he was "moved" when he read the letter.
Updates on this story and more from Nottinghamshire
The year-three pupil signed off with the words: "Please give money to charities. PS Don't give me anything else."
Speaking about his message, Aarush said: "In Syria, basically every day someone gets killed, and just not in Syria, in India and Pakistan too.
"I don't really like war, and I've been reading about the world war and nuclear bomb in Japan and I feel I don't really like it.
"Syria is like a mini version of a world war happening in one place and I thought I should write about Syria.
"Some people starve there. We are lucky that we have food here, and I'm lucky to come to this school and my mum and dad can educate me this much."
Teacher Richard Miller said he was "quite struck" by Aarush's letter.
"When I was teaching the children and talking to them about writing a letter to Father Christmas, we were talking about having an introduction, saying how is it in the North Pole and writing about some of the things they would like and how to conclude a letter," he said.
"When I read Aarush's I felt emotional because it was the last thing I was expecting to read. I was really quite moved."
A seven-year-old boy has penned a Christmas letter to Santa asking for peace in Syria instead of presents.