The fibular ligament is one of the narrower ligaments of the knee that runs along the outer aspect of the knee. Most knee ligaments are flat in shape, while this ligament is more rounded. Other names for the fibular ligament include: the fibular lateral ligament, the long external lateral ligament, and the lateral collateral ligament (LCL).

It is more flexible than most other ligaments and therefore less prone to injury. This ligament is a connective ligament between the fibula and the femur. On the femur, it connects to the lateral epicondyle and then runs down and back to where it connects to the head of the fibula. When the leg is straight, the ligament is pulled tight. It relaxes as the knee is bent. The ligament is over the anterior cruciate ligament (ACL).

The ACL is the ligament most often torn during high-impact sports injuries such as basketball and football. The fibular ligament helps to stabilize the joint on the coronal plane. The coronal, or frontal, plane is a vertical plane that divides the body into anterior (front) and dorsal (back) sections. It involves both forward and backward movements of the body.