Mastitis is a multifactorial disease of mammals that has substantial implications on production, welfare, and public health, but it is far less studied in goats than in cows. A cross-sectional study with simple random sampling at the lowest unit was conducted in selected districts of Northeastern Amhara, Ethiopia, from September 2024 to May 2025. The objectives of the study were to assess knowledge, attitudes, and practices (KAP) levels of herders on mastitis in goats, estimate its prevalence, assess associated risk factors, identify bacteria, and evaluate their antimicrobial susceptibility. A semi-structured questionnaire survey was utilized to evaluate KAP levels, while a physical examination and the California mastitis test were employed to examine mastitis in goats. Laboratory tests for bacterial identification and antimicrobial resistance were conducted following standard protocols. Stata17 and WHONET software were used for statistical analyses. Out of the 275 survey participants, 30.68% reported mastitis incidents in goats during the study period. The average scores for knowledge, attitude, and practice related to mastitis were 47.78%, 69.39%, and 46.18%, respectively. The majority of respondents did not attend school, and their knowledge of causes of goat‟s mastitis, zoonotic diseases, and subclinical mastitis was significantly associated with district and age demographics. Out of the 397 lactating goats examined, mastitis prevalence was 24.74% at goat level (CM: 2.52%, SCM: 22.22%) and 16.60% in udder halves (CM: 1.39%, SCM: 15.21%). Multivariable logistic regression analysis revealed that lactation stage (OR=1.92; 95% CI: 1.89-6.30), districts (OR=3.47; 95% CI: 1.01-3.65), parity (OR=2.73; 95% CI: 1.11-6.67), and mastitis history (OR = 13.6; 95% CI: 4.64-40.15) (p<0.05) were statistically associated with the occurrence of goat mastitis. Upon bacterial isolation and identification, the most common bacterial isolate was Staphylococcus (39.83%), followed by E. coli (10.17%), Enterococcus, Micrococcus, and Klebsiella (all < 5%). Staphylococcus was resistant to ampicillin and tetracycline, with a multidrug-resistant (MDR) prevalence of 21.16%, whereas E. coli was resistant to ampicillin, with an MDR prevalence of 8.3%. The overall MDR prevalence was found to be 17.31%. In conclusion, herders lacked good knowledge and practices about mastitis and zoonotic risks, which most likely contributed to the high prevalence of mastitis and antimicrobials -resistant bacteria. As a result, tailored training on the causes of mastitis and zoonotic risks, control and prevention for goat farmers, and further research on bacterial species and resistance factor identification are recommended. Furthermore, kanamycin and gentamycin were found to be effective against staphylococci and thus recommended for use, while tetracycline and streptomycin were found to be effective against E. coli and thus recommended.