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We consider the production of secondary gravity waves in Galileon inflation
with an ultra-slow roll (USR) phase and show that the spectrum of
scalar-induced gravitational waves (SIGWs) in this case is consistent with the
recent NANOGrav 15-year data and with sensitivities of other ground and
space-based missions, LISA, BBO, DECIGO, CE, ET, HLVK (consists of aLIGO,
aVirgo, and KAGRA), and HLV(03). Thanks to the non-renormalization property of
Galileon theory, the amplitude of the large fluctuation is controllable at the
sharp transitions between SR and USR regions. We show that the behaviour of the
GW spectrum, when one-loop effects are included in the scalar power spectrum,
is preserved under a shift of the sharp transition scale with peak amplitude
$\Omega_{\rm GW}h^2\sim {\cal O}(10^{-6})$, and hence it can cover a wide range
of frequencies within ${\cal O}(10^{-9}{\rm Hz} - 10^{7}{\rm Hz})$. An analysis
of the allowed mass range for primordial black holes (PBHs) is also performed,
where we find that mass values ranging from ${\cal O}(1M_{\odot} -
10^{-18}M_{\odot})$ can be generated over the corresponding allowed range of
low and high frequencies.