申请新加坡国籍的条件第四条：


Eligibility 里面最后一条：

Child born outside Singapore where at least one parent is a Singapore Citizen.

这种情况里的最后一条就是针对婚外私生子的：
An overseas-born minor (child) may be eligible for Singapore Citizenship by Descent under Article 122(1) of the Constitution of the Republic of Singapore, if his/her parents meet any of the following conditions:

Male Singapore citizen by Birth who has a lawful marriage at time of minor's birth

Male Singapore citizen by Registration who has a lawful marriage at time of minor's birth and minor does not acquire citizenship of the country he was born by reason of his birth in that country

Female Singapore citizen by Birth and minor born on or after 15 May 2004

Female Singapore citizen by Registration and minor born on or after 15 May 2004. Minor shall not acquire citizenship of the country he was born by reason of his birth in that country

Male (who has a lawful marriage at time of minor's birth) or Female Singapore citizen by Descent has to declare their residence period in Singapore. The application can only be accepted if the parent fulfils the requirements stipulated in the Annex.

链接：http://www.ica.gov.sg/page.aspx?pageid=132

又看了birth cert登记的条件，本地生报出生证必需要有结婚证，这也是为何非婚生子申请坡籍的情况只适用于海外出生（得选不需要结婚证就能登记出生证的地方啊），父母一方是公民的孩子。感觉新加坡男人在海外有情人甚至私生子的情况应该不罕见...新加坡缺孩子，估计不会让他们流落海外。