The phrase "concluding speech" is correct and usable in written English.
It can be used in the context of a speech or presentation given by someone which is coming to an end. For example, "The mayor gave a heartfelt concluding speech before cutting the ribbon and officially opening the long-awaited park."
King's concluding speech was a live broadcast of his 1967 Christmas Eve sermon at Ebenezer Baptist Church, "A Christmas Sermon on Peace". The sermon illuminates King's long-term vision of nonviolence as a path to world peace and contains many of King's classical oratorical set pieces, including his description of agape.
When the film was released, John C. Mosher reviewed it for The New Yorker; his response to the concluding speech suggests the scene's overwhelming power: Ghetto scenes and palace scenes have this young gusto about them, which is surely sustained through the first half but begins to abate from then on, until, all of a sudden, without any warning, Charlie Chaplin grows old.
In his concluding speech Williams held forth commitment to the process, openness to feedback, energy, enthusiasm, and passion for innovation and entrepreneurship as the key ingredients to the successful weekend.
His concluding speech over, Butler near tears, his passion spent, quietly announced he would support impeachment, but "there will be no joy in it for me".
The Commission noted that 'the Jews do not claim any proprietorship to the Wall or to the Pavement in front of it (concluding speech of Jewish Counsel, Minutes, page 908).' David Yellin, Head of the Hebrew Teachers Seminary, member of the Ottoman parliament, and one of the first public figures to join the Zionist movement openly, testified before the Commission.
"Certainly, the Synod was not about settling all the issues having to do with the family, but rather attempting to see them in the light of the Gospel and the church's tradition and two-thousand-year history, bringing the joy of hope without falling into a facile repetition of what is obvious or has already been said," the Pope said in his concluding speech.
You find them in classic ads, on social media, they start and conclude speeches.
If you are third speaker, you must also memorize how to introduce and conclude speeches for the first and second speakers (including definition of the topic, outlining your team's case, etc).
Then, concluding his speech, he said, "My bride is with me, Virginia Thomas, and some of you may know her.
Concluding his speech, Mr. Romney returned to the portrait of himself as a leader, not a Washington insider.
