Abstract: A portable toilet seat to be removably mounted on toilet installations that include an upper rim surface. The seat has two arched seat members, each having an upper half and a lower half that are securely mounted to each other, and each one of said arched seat members has an internal longitudinal channel. Two pairs of hingedly mounted arm members slidably housed inside the longitudinal channel so that when the two pairs of hingedly mounted arm members slide out and the arm members can be coaxially disposed when extended. The portable toilet seat adopts a substantially circular configuration that cooperatively aligns with the toilet rim surface. Locking mechanisms are provided to the hingedly mounted arm members so that they stay in place when housed within said arched seat members.