Background: Familial hypercholesterolemia (FH) carries a high risk of atherosclerotic cardiovascular disease (ASCVD). As the population ages, the age-related influence on clinical characteristics and outcomes becomes increasingly pertinent. This cross-sectional analysis from the HELLAS-FH registry aims to explore potential differences in clinical characteristics, treatment, ASCVD, and goal achievement between those younger and older than 65 years with FH. Results: A total of 2273 adults with heterozygous FH (51.4% males) were studied. Elderly FH patients (n = 349) had a higher prevalence of ASCVD risk factors, such as hypertension (52.1% vs. 20.9%, p < 0.05) and type 2 diabetes (16.9% vs. 6.0%, p < 0.05), compared to younger patients (n = 1924). They also had a higher prevalence of established ASCVD (38.4% vs. 23.1%, p < 0.001), particularly CAD (33.0% vs. 20.2%, p < 0.001), even after adjusting for major ASCVD risk factors. Elderly patients were more frequently and intensively receiving lipid-lowering treatment than younger ones. Although post-treatment LDL-C levels were lower in elderly than younger patients (125 vs. 146 mg/dL, p < 0.05), both groups had similar attainment of the LDL-C target (3.7% vs. 3.0%). Conclusions: Elderly FH patients have a higher prevalence of ASCVD, particularly CAD. Despite more aggressive treatment, the achievement of LDL-C targets remains very poor. These results emphasize the importance of early FH diagnosis and treatment in reducing ASCVD.