The phrase "an opening speech" is correct and usable in written English.
It can be used when referring to a speech that is delivered at the beginning of an event, ceremony, or meeting.
Example: "The mayor delivered an opening speech to welcome all the attendees to the annual festival."
Alternatives: "a keynote address" or "a welcome speech".
At the beginning, Prof. Yasunao Hattori, the president of Shimane University, Japan, declared the conference to open on behalf of the organizers, and delivered an opening speech to welcome all the distinguished scholars and experts from all over the world.
Prof. Fei Xu has declared the conference open on behalf of the organizer, Southwest Jiaotong University (SWJTU), and delivered an opening speech to welcome all the distinguished scholars and experts from all over the world.
He proceeds to give an opening speech that is funny, wry and moving.
"Although Latin music takes many forms, the spirit of diversity also unifies us," President Obama said in an opening speech.
He did so in an opening speech that showcased Conservative policies on the environment and civil liberties.
After an opening speech by Iraq's interim prime minister, Ayad Allawi, delegates leapt out of their seats demanding the conference be suspended.
In his first public appearance since he accepted his election defeat and resigned as Yugoslavia's president on Oct. 6, a day after the uprising, Mr. Milosevic gave an aggressive opening speech to the congress.
Except for a brief opening speech, not a word is spoken, and many parents may find themselves, as I did, providing whispered narration.
"I'm angry at senior video game figures that can't talk about the culture of video games," he says in an impassioned opening speech to kick off Feral Vector's festivities.
Before the plane landed, I had a powerful opening speech written as though it had been dictated.
The debate had a fine opening speech from Peter Lilley, alternately teasing the coalition members and giving them amiable warning of the differences between them.
