Songdo First World, Residential tower in Songdo, South Korea.

Songdo First World is a residential complex in Songdo International Business District, Incheon, with 14 buildings and 2,654 units. It has four 64-storey tower-type apartment blocks, two 27-storey slab-type blocks, and lower buildings for offices, shops and a community centre. The towers have large openings for ventilation and varied facade lines.

The complex was built as part of the early development of the Songdo International Business District, a planned city constructed on land reclaimed from the sea near Incheon. It stands as one of the first large residential projects completed in this new district.

The name First World refers to the complex's ambition as the first completed residential project in Songdo IBD. Its 14 buildings include four 64-storey towers, two 27-storey slab blocks, and lower officetel and retail structures, with 2,654 units in total. The complex appears in the 2018 Japanese film Detective Conan: Zero the Enforcer.

The complex is in central Songdo, which is connected to Incheon and Seoul by subway and bus. Because the building is divided into four separate court communities each with its own entrances, it helps to look for signage when moving between sections.

The four tower blocks are pierced by large openings that serve as ventilation channels and were shaped for visual effect; the complex's layout also follows wind paths. Heights, gaps between buildings and facade proportions were set according to the Fibonacci sequence, the so-called golden ratio also found in nautilus shells and Leonardo da Vinci's works.