Background: Genomic and immunologic tumor biomarker testing has dramatically changed the prognosis of patients, particularly those treated for advanced/metastatic non-squamous non-small-cell lung cancer (aNSCLC) when access to targeted agents is available. It remains unclear whether older patients have access to therapy-predictive biomarker testing techniques in the same proportion as younger patients. This study aims to compare the proportion of biomarker testing performed in non-squamous aNSCLC at diagnosis between patients aged ≥70 years old and their younger counterparts. Methods: We conducted a retrospective analysis using the Epidemio-Strategy and Medical Economics (ESME) Advanced or Metastatic Lung Cancer Data Platform, a French multicenter real-life database. All patients with non-squamous aNSCLC diagnosed between 2015 and 2018 were selected. Biomarker testing corresponded to at least one molecular alteration and/or PD-L1 testing performed within 1 month before or 3 months after the aNSCLC diagnosis. Results: In total, 2848 patients aged ≥70 years and 6900 patients aged <70 years were included. Most patients were male. The proportion of current smokers at diagnosis was higher in the <70 years group (42% vs. 17%, p < 0.0001). There was no significant difference in the proportion of biomarker testing performed between the two groups (63% vs. 65%, p = 0.15). EGFR mutations were significantly more common in the older group (22% vs. 12%, p < 0.0001) and KRAS mutations significantly more frequent in the younger group (39% vs. 31% p < 0.0001). The distribution of other driver mutations (ALK, ROS1, BRAF V600E, HER2, and MET) was similar across age. In the multivariable analysis, factors independently associated with biomarker testing were gender, smoking status, history of COPD, stage at primary diagnosis, and histological type. Conclusions: Age is not a barrier to biomarker testing in patients with aNSCLC.