Streptococcus agalactiae, also known as group B Streptococcus, is an important human and animal pathogen. Zinc (Zn) is an essential trace element for normal bacterial physiology but intoxicates bacteria at high concentrations. Molecular systems for Zn detoxification exist inS. agalactiae, however the degree to which Zn detoxification may vary among differentS. agalactiaeisolates is not clear. We measured resistance to Zn intoxication in a diverse collection of clinical isolates ofS. agalactiaeby comparing the growth of the bacteria in defined conditions of Zn stress. We found significant differences in the ability of differentS. agalactiaeisolates to resist Zn intoxication; some strains such asS. agalactiae18RS21 were able to survive and grow at 3.8-fold higher levels of Zn stress compared to other reference strains such as BM110 (6.4mM vs 1.68mM Zn as inhibitory, respectively). We performedin silicoanalysis of the available genomes of theS. agalactiaeisolates used in this study to examine the sequence ofczcD, which encodes an efflux protein for Zn that supports resistance inS. agalactiae. Interestingly, this revealed the presence of a mobile insertion sequence (IS) element, termedIS1381, in the 5′ region ofczcDinS. agalactiaestrain 834, which was hyper-resistant to Zn intoxication. Interrogating a wider collection ofS. agalactiaegenomes revealed identical placement ofIS1381 inczcDin other isolates from the clonal-complex-19 (CC19) 19 lineage. Collectively, these results show a resistance spectrum amongS. agalactiaeisolates enables survival in varying degrees of Zn stress, and this phenotypic variability has implications for understanding bacterial survival in metal stress.