Prince George, 13, looks grown up in school uniform in Eton College portraits

Prince George looks all grown up in his official Eton College portraits.

The 13-year-old royal debuted his uniform while flashing a big smile on his first day of school Tuesday.

George’s outfit included a black tailcoat, waistcoat, pinstriped pants and a white shirt with a stiff collar.

In one pic, he put his hands in his pockets, while other snaps showed him elegantly folding his hands in front of him.

George was accompanied by his parents, Prince William and Kate Middleton, as he arrived for his first day at Eton College in Berkshire, England.

The Prince and Princess of Wales braved the rain as they walked with their eldest child into William’s alma mater.

George initially wore a black suit, a blue tie and brown shoes before changing into his school uniform.

William, 44, attended Eton College from 1995 to 2000.

The future king was 13 years old when he arrived for his first day with his then-separated parents, Princess Diana and then-Prince Charles.

Meanwhile, his brother, Prince Harry, attended the prestigious school from 1998 to 2003.

When he dropped George off for school on Tuesday, William wore a black suit with a blue tie and brown shoes, keeping a closed umbrella by his side.

Middleton, meanwhile, looked elegant in a forest green dress paired with sleek curls and black pumps. She held a black umbrella over her head.

Headmaster Simon Henderson and Sir Nicholas Coleridge, the provost of Eton and the chair of the governing body, welcomed the couple and George to the all-boys school.

William and Middleton’s youngest children, Princess Charlotte and Prince Louis — who attend the Lambrook School in Berkshire, near Ascot — were not present.

In June, William and Middleton confirmed to Page Six via a Kensington Palace spokesperson that George would attend Eton College, following in his father’s footsteps.

Eton College is an all-boys boarding school founded in 1440 and is the largest boarding school in England.

Following news of his school choice, royal commentator Kinsey Schofield told Page Six that George’s “biggest challenge won’t be academics or making friends,” but “balancing [his] privacy with the reality that every classmate has TikTok.”

“William and [his brother] Harry attended before social media transformed adolescence. George won’t have that luxury, ” she continued.

Additionally, Schofield told us that George is expected to have his own room as “Eton students don’t typically have roommates.”

“That means Prince George’s protection will almost certainly be more sophisticated, even if it’s designed to remain largely invisible.”

But George will still be “immersed in a social environment” and is expected to join the athletics program, Schofield said.