A person who is currently employed or engaged in work; often used in economic or statistical contexts.
The number of employed persons in this region is on the rise.
労働者 is a broader term for 'worker' or 'laborer', not necessarily emphasizing current employment status.
失業者 is a person without a job, while 就業者 is a person who is currently employed.
Compound of 就業 (しゅうぎょう, 'employment') + 者 (しゃ, 'person').