Tibial dyschondroplasia (TD) is a leg disorder caused by the abnormal development of the tibia in fast-growing poultry. Lactobacillus rhamnosus (L. rhamnosus) strains have been reported to have effects on increasing bone growth and improving osteoporosis in animals. However, whether L. rhamnosus JYLR-005 can improve bone growth in TD chickens remains unclear. In this study, we noted that L. rhamnosus JYLR-005 could not reduce the suppression of the production performance of TD broilers (p > 0.05) but had a slight protective effect on the broiler survival rate (χ = 5.571, p = 0.062). However, for thiram-induced TD broiler chickens, L. rhamnosus JYLR-005 could promote tibia growth by increasing tibia-related parameters, including the tibia weight (day 11, p = 0.040), tibia length (day 15, p = 0.013), and tibia mean diameter (day 15, p = 0.035). Moreover, L. rhamnosus JYLR-005 supplementation improved the normal growth and development of the tibial growth plate by maintaining the morphological structure of the chondrocytes and restored the balance of calcium and phosphorus. Taken together, these findings provide a proof of principle that L. rhamnosus JYLR-005 may represent a therapeutic strategy to treat leg disease in chickens.