Abstract: Various embodiments include a locking catheter splice assembly that may include a multi-stage barb fitting, a first locking member, and a second locking member. The multi-stage barb fitting may have a first end including a first set of barbs and a second end including a second set of barbs. The first end may be configured to be inserted into the first catheter and the second end may be configured to be inserted into the second catheter. The first locking member may be slipped over the first catheter so as to surround the portion of the first end of the multi-stage barb inserted into the first catheter. The second locking member may be slipped over the second catheter so as to surround the portion of the second end of the multi-stage barb inserted into the second catheter. The first and second locking members may interlock with one another when pressed together.