Methods and devices for fixation of soft tissue to bone are provided. In one embodiment, a suture anchor is provided having an elongate cylindrical body with proximal and distal ends and an inner lumen extending therethrough. The elongate body can be configured so that upon partial insertion into a bone hole, it is securely anchored within the bone hole and a suture extending through the inner lumen is freely slidable. It can also configured so that, upon further insertion into the bone hole, at least a portion of the elongate body compresses to lock the suture within the inner lumen such that the suture is prevented from sliding. In another embodiment, a suture anchor is provided having arms that have an open position for receiving a suture therebetween, and a closed position in which the suture is retained but allowed to slide freely.