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Cosmological solitonic objects such as monopoles, cosmic strings, domain
walls, oscillons and Q-balls often appear in theories of the early Universe. We
demonstrate that such scenarios are generically accompanied by a novel
production source of gravitational waves stemming from soliton isocurvature
perturbations. The resulting induced universal gravitational waves (UGWs)
reside at lower frequencies compared to gravitational waves typically
associated with soliton formation. We show that UGWs from axion-like particle
(ALP) oscillons, originating from ALP misalignment, extend the frequency range
of produced gravitational waves by more than two orders of magnitude regardless
of the ALP mass and decay constant and can be observable in upcoming
gravitational wave experiments. UGWs open a new route for gravitational wave
signatures in broad classes of cosmological theories.