My father is a construction worker.
She is a factory worker.

Common collocations:
factory worker
agricultural/farm worker
construction worker
office worker

While worker is suitable to describe employees who do manual work, the word labourer is often used for people who do physically demanding work.

Examples:
agricultural labourer
building labourer

Other uses
the workers was a term commonly used by communist and other social revolutionaries and reformers and often appeared in their slogans:

Workers of the world unite! You have nothing to lose but your chains!
Up the workers!
The workers' flag is deepest red...