Division Street, in the city centre, was crammed with blue and yellow shirts as Sweden fans enjoyed a Yorkshire mixture of sunny spells and drizzle with songs accompanied by a relentless bass drum.
England fans seemed to be leaving it a little later to begin their pre-match rituals but two fan parks in the city are expected to be crammed by kick-off at 8pm, with the match screened live on Devonshire Green.
Around 1,500 Sweden fans are expected in Sheffield for the match.
Sisters Caroline and Ida Gunnarsson, 24 and 17, were leading the partying outside the Frog and Parrot pub.
Caroline said: “It amazing here. We are loving it.
“The English people are just amazing.”
Jonny Spence, 24, from Barnsley, said: “They’re outsinging us now but it’ll be different come kick-off.”
Every hotel room in Sheffield has reported to have been snapped up for the much-anticipated Euro clash.
Fixtures at Bramall Lane so far in the tournament have already set new records for group stage matches not involving the host, with 21,342 attending Sweden’s clash with Holland and 22,596 witnessing their victory over Switzerland.
Sheffield City Council estimates 7,500 international fans have attended fixtures in the city.
The council said that footfall was up by 22%, more than 10,000, on the Saturday of the opening fixture in Sheffield, compared to the previous Saturday.
And it said the economic impact for the city, which has put its hat in the ring to host next year’s Eurovision Song Contest, is expected to be around £3 million.