The picture shows Jameson looking directly into the camera wearing a blue colour coordinated outfit, a star-printed mask, and of course his backpack, ready to tackle this new adventure.
"Jameson's 1st day of pre school. He is growing like a weed!!!!! So proud of you, lil man," the proud dad wrote in the Instagram post.
Jameson's first day at pre-school come after he battled COVID-19 alongside his mother last year. Pink has spoken of how difficult the experience was for the famous family.
"Battling COVID-19 along with my 3-year-old son was the most physically and emotionally challenging experience I have gone through as a mother. Weeks after receiving our test results, my son was still ill and feverish. It was a terrifying time, not knowing what might come next," the singer wrote in an opinion article published by NBC News.
"I have been reflecting on the wonderful, yet challenging gift of time that life in COVID-19 quarantine has meant for me and my children."