On Independence Day, the country's red, black and yellow flag is everywhere - hanging from houses, flapping from cars, painted on children's faces. Towns hold big parades with marching bands, school choirs, traditional dancers, and sports displays. Many people wear their best traditional costumes from their home province.
Most schools take part. Children practise songs and dances for weeks beforehand. On the day, they march around the school playing field, line up to sing the national anthem, and hold up posters they have drawn about what they love about PNG. Then there is usually a feast - a class mumu, plates of rice and chicken, fresh fruit, and lots of music.
Each of PNG's 22 provinces has its own way of celebrating. In Port Moresby, the capital, there are big concerts and fireworks. In the Highlands, towns hold sing-sings with hundreds of dancers. On the islands, communities hold canoe races on the sea. Across the whole country, it is a day for being proud of being from PNG.
The national motto is 'Unity in Diversity'. That means: lots of different languages, lots of different cultures, lots of different islands - all part of one country. Independence Day is when the country celebrates that idea. Hundreds of different groups, all in the same big family.