Human milk oligosaccharides offer unique benefits for infant growth and development. Buffalo milk, characterized by a mild flavor and high nutritional value, has attracted considerable interest. To characterize the oligosaccharide profile and composition of buffalo milk, we conducted qualitative and quantitative analysis of milk oligosaccharides at the early- and late-lactation stages of crossbred (Nili-Ravi × Murrah × local) buffaloes from Guangxi, China. The results revealed a total of 97 oligosaccharides including 17 novel oligosaccharides, with concentrations of 416.6 ± 25.86 and 368.3 ± 10.29 mg/L in milk from early- and late-lactation stages, respectively. The most abundant oligosaccharides were 3’-sialyllactose (3’-SL), difucosyllactose (DFL), 6’-sialyllactose (6’-SL), and a newly discovered compound, 2142. The oligosaccharides in crossbred (Nili-Ravi × Murrah × local) buffaloes demonstrated greater diversity than those found in the milk of other dairy animals, highlighting its potential as a high-quality nutritional resource for adults and infants.