The Youth Theme exemplifies the aspirations, ruggedness and community spirit of youths in Singapore. Found on the back of the $100 note, this is represented by three aspects of youth activities, namely Youth in Community Service, Youth in Action and Youth in Leadership Development. On the left of the design is a group of uniformed youths representing the Singapore Red Cross, St John's Ambulance Brigade and National Police Cadet Corps. Situated in the centre of the design is a group of scouts engaged in an outdoor scouting activity. On the right, a National Service officer bearing a ceremonial sword stands against a backdrop of the magnificent tower of the SAFTI military institute.

The $100 note also carries the picture of the Swallow Cowrie (Cypraea hirundo Linnaeus, 1758). The mollusc is found over much of the Indo-West Pacific region and usually lives on wave-beaten reefs at low tide, under coral slabs and rocks. This species was originally described from Mauritius and India with other variations reported from as far as northwestern Australia and Japan.

The shell of this animal has two distinct dark brown spots on the ends and the surface is bluish green with minute brown speckles. It is moderately common in shallow rocky habitats.