A person who presents or speaks at a meeting, conference, or event; a presenter/speaker.
明日の学会で私は発表者として30分間話します。
At tomorrow's conference I'll speak for 30 minutes as a presenter.
発表者は資料を事前に参加者に配布してください。
Please distribute the presenter's materials to participants in advance.
会議の発表者が増えて、時間配分を見直す必要がある。
The number of presenters for the meeting has increased, so we need to revise the time allocation.