A clamp for selectively compressing a portion of tubing, such as an extension leg of a PICC or other catheter, is disclosed. The clamp is able to be opened or closed with a thumb and finger of a single hand of a user and is slidably attached to the tubing so as to enable its placement as desired along the tube. In one embodiment, the tubing clamp comprises a body including first and second body portions hingedly connected to one another in a clamshell configuration, a latch for releasably latching the first and second body portions together, and at least two tube compression members. The tube compression members cooperate to compress and occlude a portion of tubing passing through the tubing clamp when the first and second body portions are latched to one another.