This chapter provides an overview of contemporary research into formulaic sequences (FSs) in L2 speech. We start with a working definition of FSs with examples, followed by a discussion on the history of research and teaching FSs, and descriptions of both early and recent publications to shed light on different stages of development of these areas. We then elaborate on the critical issues under investigation to date, namely the pervasiveness of FSs in speech, their relationship with speaking proficiency, their role in oral fluency, and then the challenges they pose to L2 learners. Next, contributions of current research are outlined, showing the latest trends in research on FSs, such as studies adopting multivariate approaches or those focusing on input for FS learning. Main research methods that have been employed in relevant studies are summarized before research-informed suggestions for practice are provided, including providing authentic input, teaching FSs explicitly, and providing output activities along with fluency training. To conclude, future directions are discussed, calling for further investigations including languages other than English, involving more diversified learners, and examining more pedagogic interventions on FSs and speech.