Flow controllers for intravenous (IV) tubing are provided. A flow controller may include a first structural member comprising a first outer surface and a first inner surface disposed at an angle to the first outer surface, a second structural member comprising a second outer surface parallel to the first outer surface and a second continuous inner surface parallel to the first inner surface, and a third structural member disposed on one of the first or second structural member and having a friction-reducing surface for at least a portion of a cavity disposed between the first and second structural members. The first structural member is linearly slidable along a length of the IV tubing disposed in the cavity to compress a portion of the IV tubing to control flow of a medical fluid through the IV tubing. Other flow controllers and IV sets that include a flow controller are also provided.