Across-sectional study was conducted from November 2020 to April 2021in and around Bahir Dar dairy farms to isolate, identify and to determine antimicrobial susceptibility pattern of Streptococcus agalactiae from bovine mastitic milk. The samples were taken from clinically diseased and California Mastitis Test positive cows with Purposive sampling method. Isolation and identification of an organism was based on morphological, cultural and biochemical characteristics. A total of 123 lactating cows were tested for isolation and identification of the bacteria, of which 8 (6.50%) were clinical and 63 (51.22%) were sub-clinical mastitis. Those California Mastitis Test positive samples and samples from clinical samples were cultured on different culturing Medias. Out of the total 63 subclinical mastitis 9 samples and from 8 clinical mastitis 3 samples were further identified using primary and secondary biochemical tests. A total of 12/71 (16.90%) milk samples were shown typical catalase negative and CAMP test positive resulted in positive for Streptococcus agalactiae. The risk factors, breed, age, parity, and lactation stage, were found associated statistically significant (P<0.05) with the occurrence of mastitis due to Streptococcus agalactiae. The bacteria were 100% susceptible to vancomycin, erythromycin, and clindamycin. The microorganism was also sensitive to tetracyclin (91.67%), and ampicillin (83.33%). However, it was not susceptible to penicillin (100%). Regular antimicrobial susceptibility tests against Streptococcus agalactiae should be conducted in order to monitor the effectiveness of drugs against the pathogen. Veterinarians should be advised to use vancomycin, erythromycin, clindamycin and tetracyclin in dairy farms against mastitis caused by Streptococcus agalactiae. Key words: Bahir Dar; identification; isolation; mastitic milk; Streptococcus agalactiae