The current standard treatment for surgical site infections (SSIs) is marked by prolonged courses of antibiotics, which have limitations due to antibiotic resistance, systemic side effects, and poor patient adherence. We developed a novel injectable alginate/collagen clindamycin hydrogel that rapidly solidifies upon injection and allows for initial burst release followed by sustained release to maintain therapeutic levels. The rheological, morphological, and in-vitro release kinetics of the hydrogel were characterized. Furthermore, with an in-vivo murine SSI model incubated with logarithmic growth phase 1 × 10