Yttrium oxide cluster cations have been experimentally and theoretically studied. We produced small, oxygen-rich yttrium oxide clusters, YxOy+; (x = 1, 2, y = 1-13), by mixing the laser-produced yttrium plasma with a molecular oxygen jet. Mass spectrometry measurements showed that the most stable clusters are those consisting of one yttrium and an odd number of oxygen atoms of the form YO2k+1+ (k = 0-6). Additionally, we performed collision induced dissociation experiments, which indicated that the loss of pairs of oxygen atoms down to a YO+ core is the preferred fragmentation channel for all clusters investigated. Furthermore, we conduct DFT calculations and we obtained two types of low-energy structures: one containing an yttrium cation core and the other composed of YO+ core and O-2 ligands, being in agreement with the observed fragmentation pattern. Finally, from the fragmentation studies, total collision cross sections are obtained and these are compared with geometrical cross sections of the calculated structures.