Name all the countries that have overseas territories. In addition, name the largest and most populated territories of each country. In terms of disputed territories, the country that has asserted the most dominance in the region will be listed.
https://www.worldatlas.com/dependtr.htm
Antarctic territories not included
One territory is not overseas, but requires immigration forms from citizens of its host country, therefore it will be included
You are right, there is an island section of Hong Kong which I was thinking about but it is a peninsula. Because of the fact that Chinese citizens going to Hong Kong have to go through such a large immigration process, I will leave it but I will add a caveat explaining this.
Not clear what's a territory and what isn't. For example, the French call French Guiana part of France. So, if you include that, why haven't you included Ceuta and Melilla as parts of Spain? And if Svalbard counts as an overseas part of Norway, why aren't the canary islands overseas parts of Spain and Madeira an overseas part of Portugal?
It is a bit arbitrary actually. It just depends on if the government decides to fully integrate a piece of land in the legal system or not. For example, in the French empire, Algeria was considered a part of metropolitan France despite being in Africa. In Canada, the Northwestern Territories are connected by land to Canada but still considered a territory. If you look at my source, you will probably be able to find the answers you were seeking.