"Spider-Man: Brand New Day" opened to a record-breaking start at the South Korean box office over the weekend of 31 July–2 August, dominating cinemas so completely that it accounted for more than four in five tickets sold nationwide. The scale of the debut illustrates the continued pull of major Hollywood tentpoles in the territory and pushed previous frontrunner "Hope" into second place after a fortnight at the top.

According to KOBIS, the tracking service run by the Korean Film Council, the film earned $16.9 million from 2,252,930 admissions over the three-day weekend across 2,409 screens, taking an 80.63% share of total box office revenue. Since its wide release on 29 July, it has grossed $25 million from 3,384,147 admissions in total, with $2.4 million of that coming from Imax screens, marking the biggest Imax opening weekend ever recorded in South Korea. Further down the chart, local sci-fi thriller "Hope" added $2.4 million to reach $31 million overall, while "Minions & Monsters", "Moana" and "Toy Story 5" rounded out the top five.