The youngster was introduced to prime ministers and presidents by his mother Carrie Johnson at the event in Carbis Bay, Cornwall, on Saturday evening.
Wilfred, who was wearing a white shirt and blue shorts, was pictured waddling towards his proud mother.
First Lady Jill Biden and Brigitte Macron beamed at the toddler, who was sporting a very familiar mop of tousled blond hair.
G7 leaders appeared to be in high spirits at the sun-drenched event, with Mr Johnson enjoying a bottle of Tribute pale ale.
He looked relaxed as he chatted to Emmanuel Macron, just hours after serious discussion with with French President about post-Brexit trade arrangements in Northern Ireland.
Mr Johnson also spoke to a Red Arrows pilot following an impressive display by the RAF aerobatics team.
The group watched on as Hawk fast jets looped around into their famous diamond shape several times before splitting off.
Following the display, Mr Johnson tweeted: "What a sight! Thank you to the incredible @rafredarrows for an amazing show."
The three-day summit is scheduled to end on Sunday, and the leaders are expected to commit to a new plan, called the Carbis Bay Declaration, to subdue future pandemics within the first 100 days.
The leaders of the G7 - the UK, US, Canada, Japan, France, Germany and Italy - will promise to adopt measures aimed at slashing the time taken to develop and license vaccines, treatments and diagnostics for any future disease.
Mr Johnson said: "In the last year the world has developed several effective coronavirus vaccines, licensed and manufactured them at pace and is now getting them into the arms of the people who need them.
"But to truly defeat coronavirus and recover we need to prevent a pandemic like this from ever happening again. That means learning lessons from the last 18 months and doing it differently next time around.
"I am proud that for the first time today the world’s leading democracies have come together to make sure that never again will we be caught unawares."
While the G7 summit has been packed with meetings and social events, the PM discussed the possibility of delaying June 21, dubbed “Freedom Day” due to the spread of the Delta variant.
He told Sky News: “It’s clear that the Indian variant is more transmissible and it’s also true that the cases are going up, and that the levels of hospitalisation are going up.
“Now, we don’t know exactly to what extent that is going to feed through into extra mortality, but clearly it’s a matter of serious, serious concern.”
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