Abstract: A slip bobber for a fishing line includes a pair of separable parts that abut on each other at respective transverse mating surfaces to form a buoyant body. The mating surface of one of the parts has a diametral groove dimensioned for slidable reception of a fishing line. An externally-threaded post projects outwardly from this surface and has a longitudinal line-receiving slot extending transversely through the post and in register with the groove. The mating surface of the other part includes an opening in register with the post and dimensioned for receiving the post in threaded engagement for bringing the parts into abutting engagement. A resilient flexible wall preferably provides the latter mating surface and is stressed to enhance engagement and resist separation of the parts.