Bacteria of the genus Streptococcus are common causative agents of infections in various organ systems of horses. The most important streptococcal species in horses, Streptococcus equi subsp. equi (S. equi), Streptococcus equi subsp. zooepidemicus (S. zooepidemicus), and Streptococcus dysgalactiae subsp. equisimilis (S. equisimilis), produce beta-hemolysis on blood agar, and therefore belong to the group of beta-hemolytic streptococci (BHS). The aim of this study was to investigate the occurrence of BHS isolated from clinical samples of horses, species distribution, and their antimicrobial susceptibility over the period from 2013 to 2022. Over the nine-year period, 96 isolates of beta-hemolytic streptococci were isolated from 803 clinical samples, of which 73 isolates were preserved for further analysis and included in this study. The majority of BHS isolates (50.7%) originated from the respiratory system. BHS species were identified using commercial biochemical tests (API) and the MALDI-TOF MS method. The most common BHS species were S. zooepidemicus (72.6%) and S. equisimilis (19.2%). Most of the S. zooepidemicus isolates (55%) were from the respiratory system, as were half of the S. equisimilis isolates (50%). All BHS isolates were susceptible to penicillin and ceftiofur. Majority (96.2%) of the S. zooepidemicus isolates were susceptible to trimethoprim/sulfamethoxazole, and 73.6% to enrofloxacin. Majority (92.9%) of the S. equisimilis isolates were susceptible to trimethoprim/sulfamethoxazole and erythromycin, but only 7.1% were susceptible to enrofloxacin. The results of this study confirm the importance of BHS as causative agents of infections in horses and highlight the need for continued monitoring of antimicrobial resistance.