crucially, phases of each pulse. Phase-cycling schemes can then be applied to create and isolate the desired nonlinear signals encoded in the action response. Motivated by these studies, we have worked towards the implementation of ultrafast, frequency-resolved transient absorption (TA) and two-dimensional (2D) cryogenic ion vibrational spectroscopy (CIVS). We previously demonstrated the acquisition of linear infrared spectra of cryogenically cooled ions using an ultrafast pulse pair (Fig. ). The tag-loss photodissociation signal oscillates as a function of the delay time, τ, between the pulses due to interferences between the excited vibrational coherences, with the Fourier transform yielding the frequency-domain linear action spectrum. Very recently, we presented the acquisition of TA-CIVS where excitation by a pump pulse precedes a probe pulse pair (Fig. ). Data is again collected in the time domain as a function of the probe pair delay time to frequency resolve the probe axis. An eight-step phase-cycling scheme isolates the TA signal from background linear and double quantum pathways, allowing for the measurement of bleaching signals of the fundamental transitions that evolve with the pump-probe waiting time, Tw. Herein, we present the first 2D-CIVS spectra. Four collinear pulses, consisting of a pump pulse pair and a probe pulse pair, are used to excite tagged molecular ions (Fig. ). The tag-loss action signal is monitored as a function of both the pump pair delay, τ1, and the probe pair delay, τ3, using a 27-step phase-cycling scheme. A 2D-Fourier transform of the time-domain data produces a 2D IR spectrum that is frequency resolved along the pump and probe axes. A detailed description of the experimental methodologies and data processing procedures are provided in Supporting Information.