İn this book, the subject of old-age insurance, which is almost a guarantee for human beings, who are more limited in terms of vvorking opportunities and abilities in the old age period is mentioned. Since there is no Standard old-age insurance application among the European Union countries, the leading countries of the union on the one hand (except for England, which has lost this position after the brexit process) and developing countries within the union on another hand, were selected and focused and Turkey's old age insurance wasuated either way. We hope that the work will be useful to readers who want to leam about the Old Age insurance and especially the pension systems of these countries.