The Comet Line was a Resistance organization in occupied Belgium and France in the Second World War. The Comet Line helped Allied soldiers and airmen shot down over occupied Belgium evade capture by Germans and return to Great Britain. The Comet Line began in Brussels where the airmen were fed, clothed, given false identity papers, and hidden in attics, cellars, and people's homes. A network of volunteers then escorted them south through occupied France into neutral Spain and home via British-controlled Gibraltar. The motto of the Comet Line was "Pugna Quin Percutias", which means "fight without arms", as the organization did not undertake armed or violent resistance to the German occupation.

The Belgian Resistance collectively refers to the resistance movements opposed to the German occupation of Belgium during World War II. Within Belgium, resistance was fragmented between many separate organizations, divided by region and political stances. The resistance included both men and women from both Walloon and Flemish parts of the country. Aside from sabotage of military infrastructure in the country and assassinations of collaborators, these groups also published large numbers of underground newspapers, gathered intelligence and maintained various escape networks that helped Allied airmen trapped behind enemy lines escape from German-occupied Europe.