约翰·查尔斯·弗兰西斯·温莎（John Charles Francis Windsor，1905年7月12日-1919年1月18日），约翰王子，英国王室成员，乔治五世与玛丽王后幼子，出生于诺福克郡桑德灵厄姆庄园，自幼患有癫痫与自闭症，存在智力发育滞后情况，常年被王室隐匿于公众视野之外。约翰王子1909年首次癫痫发作，致其未能出席1911年乔治五世加冕典礼。12岁时病情加剧，被转移至伍德农场由保姆拉拉照料，期间脱离王室公开活动，日常骑马、整理花园并接触音乐，乔治王子曾评价其“是王室唯一能做自己的人”。1919年1月18日，约翰王子因突发癫痫于伍德农场去世，遗体安葬于桑德灵厄姆圣玛丽抹大拉教堂。其生前信件与玛丽王后日记显示王室对其健康状态长期担忧。

约翰王子出生于英国诺福克桑德灵厄姆庄园，他的父亲是乔治五世（爱德华七世国王和亚历山德拉王后的儿子），母亲是玛丽王后（公爵和公爵夫人泰克的长女）。

约翰王子在四岁的时候他的癫痫第一次发作。因此他没有参加1911 年 6 月 22 日他父亲的加冕礼。12 岁那年，他的病情有恶化，于是搬离皇宫送到远郊的小村庄的别墅，远离大众视线，由保姆“拉拉”看护。

1919 年 1 月 18 日凌晨，约翰王子与木材厂死亡在上午国王和王后接到王子的死讯。

后被葬于皇家园林桑德灵厄姆，与亚历山德拉王后（约翰王子的奶奶）的儿子约翰（只存活了一天就死了）葬在一起，两者相差46年。

以下是玛丽王后关于约翰王子的日记

An entry in the Queen's diary reads: 　 Lalla Bill telephoned from Wood Farm, Wolferton, that our poor darling Johnnie had died suddenly after one of his attacks. The news gave me a great shock, though for the little boy's restless soul, death came as a great release. I brought the news to George & we motored down to Wood Farm. Found poor Lalla very resigned but heartbroken. Little Johnnie looked very peaceful lying there… For him it is a great release as his malady was becoming worse as he grew older and he has thus been spared much suffering. I cannot say how grateful we feel to God for having taken him in such a peaceful way, he just slept quietly… no pain, no struggle, just peace for the poor little troubled spirit, which had been a great anxiety for us for many years ever since he was four. Prince John was buried 21 January 1919 at Sandringham Church the Church of St Mary Magdalene , Norfolk. Titles, styles, honours and arms

父亲：乔治五世

母亲：玛丽王后

奶奶：亚历山德拉皇后

爷爷：爱德华七世兄长：爱德华八世（温莎公爵）、乔治王子（死于空难）、乔治六世、亨利王子

姐姐：玛丽长公主

约翰王子的信

Dear Papa,I'm sending you a box of snowdrops for you which I have picked… these two daisies I have picked out of my garden.

May 1918

My dear papa,

I'm sending you in a box some lilies out of Wolferton Woods…The garden is very nice here… I am very busy here. Best love from your devoted son, Johnnie.