Sri Lanka
18 years of age; universal

Sudan
17 years of age; universal, but noncompulsory

Suriname
18 years of age; universal

Swaziland
18 years of age

Sweden
18 years of age; universal

Switzerland
18 years of age; universal

Syria
18 years of age; universal

Taiwan
20 years of age; universal

Tajikistan
18 years of age; universal

Tanzania
18 years of age; universal