The Manchester-based author and illustrator was awarded £10,000 at a ceremony in central London for the annual children’s book award, which is celebrating its 10th anniversary.
Jarvis’ powerful tale of “pure and poignant” friendship and being there for someone when they are at their most vulnerable topped the shortlist of six stories to take home the literary prize.
Beatrice said: “I am honoured to be a Patron of Oscar’s Book Prize.
“As befits this special tenth anniversary for the prize, the judges have chosen a truly unique book that the judges all felt is an instant modern classic.
“Its values of friendship and acceptance exemplify the very best tropes in picture book storytelling, all told with a gentle immersive world for its readers.
“It is also, in the Oscar’s Book Prize tradition, beautifully illustrated. Congratulations to Jarvis with his book, The Boy With Flowers in His Hair.”
Speaking at the event Beatrice also noted the importance of literacy to the Queen and said the coronation weekend had reminded her of the importance of community.
As befits this special tenth anniversary for the prize, the judges have chosen a truly unique book that the judges all felt is an instant modern classic.
Jarvis said: “I could not be more delighted to have won this year’s Oscar’s Book Prize, and taking a look around the room and the incredibly talented authors and illustrators also shortlisted, it truly is an honour.
“I’ve always believed that picture books are a piece of art that everyone can own.
“This award celebrates the art and joy in children’s books and I am so pleased that my book, which focuses on poignant issues surrounding vulnerability and friendship, has been received so well.”
The finalists for the prize included Billy And The Pirates by Nadia Shireen, Can I Play? by Nicola Kinnear and Frank And Bert by Chris Naylor-Ballesteros.
Meanwhile, Teapot Trouble: A Duck And Tiny Horse Adventure by Morag Hood and The Gecko And The Echo by author Rachel Bright and illustrator Jim Field were also among the shortlisted titles.
Many of this year’s judging panel joined the award ceremony at The Ivy, including author and two-time winner of the prize Benji Davies, acclaimed children’s author Cressida Cowell, Amazon’s UK books country manager Lisa De Meyer and the prize’s co-founder Viveka Alvestrand.
Alvestrand and her husband James Ashton set up the prize to “celebrate magical stories” and “encourage parents to take time to share books with their young children” in memory of their son Oscar, who died at age three-and-a-half from an undiagnosed heart condition in December 2012.
De Meyer said: “It is exciting to continue to support Oscar’s Book Prize as it reaches its tenth year.
“It’s important to be able to engage children with vibrant illustrations and moving stories and Jarvis has done this perfectly with this year’s winning book. We can’t wait to see what else Jarvis has in store!”
Jarvis has produced several children’s books during his career, including the counting book This Little Piggy and Alan’s Big, Scary Teeth.