I. INTRODUCTION 2 1 See [6] for a discussion of composite Higgs models from the effective 4D point of view. The primary goal of the Large Hadron Collider (LHC) is the study of the precise mech- anism of electroweak symmetry breaking (EWSB). One interesting possibility is that new gauge interactions become strongly coupled at the TeV scale, breaking some global symme- tries but not necessarily the electroweak gauge symmetry. The Higgs boson can then arise as a composite Goldstone boson of the spontaneous global symmetry breaking. The coupling to an elementary sector (external to the strongly coupled theory) breaks explicitly the global symmetries and generates a potential for the Higgs at the loop level [1]. The AdS/CFT correspondence [2] suggests that models with warped extra dimensions [3] are weakly cou- pled duals to strongly coupled four-dimensional (4D) conformal theories [4], and therefore they provide a calculable framework for composite Higgs models [5]. 1 A recent review of tools employed to study models with warped extra dimensions and their phenomenological implications can be found in [7]. Using a custodially symmetric set-up [8] and a fermionic content that guarantees protec- tion of the Z ¯ b$_{L}$b$_{L}$ coupling [9] (see [10] for an alternative), minimal composite Higgs models from warped extra dimensions [11] have been shown to dynamically generate EWSB at the expense of a modest fine-tuning [11–13]. Furthermore, they are fully compatible with elec- troweak precision tests (EWPT) [14, 15] and can even be easily extended to accommodate dark matter [16–18]. (How relevant is the fine-tuning is a debatable matter as it has been shown that there is a large intersection in these models among the regions with a good pat- tern of EWSB, the correct top mass and a good behaviour under EWPT [12, 17].) Most of the studies related to the five-dimensional (5D) realization of composite Higgs models have only focused on the quark sector. In fact, although some of the first studies of bulk fermion phenomenology in models with warped extra dimensions were made with the leptonic sector in mind [19–21], not much progress has been made until quite recently. In particular, older proposals for models of lepton masses have, with few exceptions, not been updated to make them compatible with new, realistic models in warped extra dimensions. One possible rea- son is that the generation of Yukawa couplings by fermion splitting [22] seemed to naturally lead to a hierarchical pattern of fermion masses and mixing angles, like the one observed in