**Abstract**

Tuberculosis (TB), caused by *Mycobacterium tuberculosis*, is a major global health concern given the increase in multiple forms of drug-resistant TB. This underscores the importance of a continuous pipeline of new anti-TB agents. From recent studies, it is evident that the increase in drug efficacy is being achieved through re-engineering old TB-drug families and repurposing known drugs. This approach has led to producing a newer class of compounds which not only saves time and investment in developing newer drugs but is also effective in identifying drug candidates with novel mechanisms to treat multi-drug resistant strains. The repurposed drugs moxifloxacin, linezolid, and clofazimine are used to treat extensively drug-resistant TB when first- and/or second-line drugs fail. The chapter covers a detailed background on the current status of the repurposed drugs in the TB drug-discovery pipeline and discusses a potential way forward.

**Keywords:** tuberculosis, repurposed drugs, drug discovery pipe-line, *Mycobacterium tuberculosis*
