The present invention provides novel phenazine derivatives, such as compounds of Formula (I) (e.g., Formulae (II)-(XIX)), and pharmaceutically acceptable salts thereof. The compounds of the invention are expected to be antimicrobial agents and may act by a microbial warfare strategy (e.g., a reactive oxygen species (ROS)-based competition strategy). The present invention also provides pharmaceutical compositions, kits, uses, and methods that involve the compounds of the invention and may be useful in preventing or treating a microbial infection (e.g., a bacterial infection or mycobacterial infection) in a subject, inhibiting the growth and/or reproduction of a microorganism (e.g., a bacterium or mycobacterium), killing a microorganism (e.g., a bacterium or mycobacterium), inhibiting the formation and/or growth of a biofilm, reducing or clearing a biofilm, and/or disinfecting a surface.