Canada–France–Hawaii Telescope Legacy Survey optical photometry has been used to study the galaxy luminosity functions (LFs) of 14 X-ray selected clusters from the XMM Large Scale Survey(XMM–LSS) survey. These are mostly groups and poor clusters, with masses around 1014 M⊙ and redshifts 0.05 ≤z≤ 0.61 . Hence, these are some of the highest redshift X-ray selected groups to have been studied. We derive individual LFs for all clusters as well as redshift-stacked and temperature-stacked LFs in three filters down to M=−14.5 . All LFs were fitted by Schechter functions which constrained the faint-end slope but did not always fit well to the bright end. Derived values of slope ranged from −1.03 to as steep as −2.1. We find no evidence for upturns at faint magnitudes. Evolution in LF slope was apparent in all bands: it becomes shallower with increasing redshift; for example, in the z' band it flattened from −1.75 at low redshift to [UTF-8?]−1.22 in the redshift range z= 0.43–0.61. We find that at [UTF-8?]z∼ 0.3 slope is steeper (−1.67) in the green (g') band than it is (−1.30) in the red (z') band. This colour trend disappears at low redshift, which we attribute to reddening of faint blue galaxies from z∼ 0.3 to 0. We calculated the total optical luminosity and found it to correlate strongly with X-ray luminosity  (LXâˆ�L2.1OPT) , and also with ICM temperature (LOPTâˆ�T1.62) , consistent with expectations for self-similar clusters with constant mass-to-light ratio. We did not find any convincing correlation of Schechter parameters with mean cluster temperature.