Bone remodeling is coordinated by the activity balance of bone formation and resorption. Therapeutics that promote bone formation have clinically gotten attention since the approval of bone anabolic agents. The primary cilium is a plasma membrane-protruding immotile sensory organelle expressed in various types of cells. Recent studies have uncovered that the primary cilium in preosteoblasts drives the differentiation of the cells to osteoblasts when the cilium receives hedgehog. However, the regulatory mechanisms of the ciliary function in preosteoblasts have been unclear. Protein 4.1G is a plasma membrane-associated cytoskeletal protein that regulates the cellular distribution of membrane proteins. 4.1G is expressed in various tissues. In addition, we recently identified the expression of 4.1G in preosteoblasts, and thus we hypothesized that 4.1G regulates bone formation. In this study, we first found that 4.1G was essential for bone formation without affecting bone morphology in the newborn tibia. As the mechanism, we found that 4.1G promotes ciliogenesis followed by the cilium-mediated hedgehog signaling and differentiation to the osteoblasts in the cells. This study provides new insight into the mechanisms of bone formation. It is expected that the 4.1G-ciliogenesis axis will become a therapeutic target for bone remodeling.