The purpose of the present study was to evaluate the effects of the football-based health education program "11 for Health" on health knowledge and well-being in the setting of a 10-week residential stay in a Danish charity home for socially vulnerable children. Six hundred and fourteen children participated in the study, of which 305 took part in the standard program plus "11 for Health" (SG+: 12.4 ± 1.4 (mean ± SD) years) and 309 took part in the standard program (SG: 12.4 ± 1.6 years). We used a crossover design over two full years. The study examined changes in health knowledge and well-being through questionnaires. Overall health knowledge increased more in SG+ than SG over 10 weeks (6.6 vs. 3.4%, p < 0.05). The overall well-being scores were markedly improved (p < 0.05) by 4.54 ± 7.17 AU in SG+ and 4.51 ± 7.16 AU in SG, with no between-group differences. Specific improvements (p < 0.05) were seen in all well-being subcategories, raising the well-being scores to the national average. In conclusion, a 10-week stay at a Danish charity home, the Christmas Seal Home, markedly affected health knowledge and well-being of socially vulnerable children. When the football-based health education program-11 for Health-was added, there were additional positive effects on health knowledge.