丝状病毒（学名：Filoviridae）属于丝状病毒科，单股反链病毒目，是一种感染脊椎动物的病毒，目前已知的属只有伊波拉病毒和马尔堡病毒。

病毒粒（Virion）具有复杂构造，具外套膜（envelope），核鞘（nucleocapsid），聚合酶复合体和基质（Matrix）。病毒粒包裹在外套膜中。病毒的外形呈丝状，或具分支多形态，或U形，6形，或圆形（特别在纯化后），病毒的直径约80nm，可达1400nm长，纯化出的病毒长度可能达790-970nm。表面有瘤状突起的形状，散布在脂质双层膜中。

The family and CDC Filoviridae (members are called Filovirus) is the taxonomic home of several related viruses that form filamentous infectious viral particles (virions), and encode their genome in the form of single-stranded negative-sense RNA. Two members of the family that are commonly known are Ebola virus and Marburg virus. Both viruses, and some of their lesser known relatives, cause severe disease in humans and nonhuman primates in the form of viral hemorrhagic fevers. All ebolaviruses and marburgviruses are Select Agents, World Health Organization Risk Group 4 Pathogens (requiring Biosafety Level 4-equivalent containment), National Institutes of Health/National Institute of Allergy and Infectious Diseases Category A Priority Pathogens, Centers for Disease Control and Prevention Category A Bioterrorism Agents, and listed as Biological Agents for Export Control by the Australia Group. It is expected that cuevaviruses will be classified in a similar way in the near future.