  The clockwork mechanism, which can naturally explain the origin of small
numbers, is implemented in $SO(10)$ grand unified theories to address the
origin of hierarchies in fermion masses and mixings. We show that a minimal
Yukawa sector involving a $10_H$ and $\overline{126}_H$ of Higgs bosons,
extended with two clockwork chains consisting of $16+\overline{16}$ vector-like
fermions, can explain the hierarchical patterns with all the Yukawa couplings
being of order one. Emergence of a realistic mass spectrum does not require any
symmetry that distinguishes the three generations. We develop
clockwork-extended $SO(10)$ GUTs both in the context of SUSY and non-SUSY
frameworks. Implementation of the mechanism in non-SUSY scenario assumes a
Peccei-Quinn symmetry realized at an intermediate scale, with the clockwork
sector carrying non-trivial charges, which solves the strong CP problem and
provides axion as a dark matter candidate.
