Refers to a business or person that arranges travel services, such as booking flights, hotels, and tours.
I asked a travel agent to arrange the flight tickets.
旅行会社 is a more common term for a travel agency or company, while 旅行業者 emphasizes the agent or operator role, often in a business or legal context.
travel agent; reseller of tour packages
Compound of 旅行 (travel) + 業者 (business operator, agent).