The phrase "a final speech" is correct and usable in written English.
It can be used when referring to the last speech given in a particular context, such as at a graduation, a farewell, or a concluding event.
Example: "During the ceremony, the principal delivered a final speech that left a lasting impression on the graduates."
Alternatives: "a concluding address" or "a closing speech".
I could feel him choosing his words, a final speech he wanted to make.
In a final speech to the Senate today, Mr. D'Alema admitted some failings that led to his coalition's humiliating defeat.
If the prisoner gave a final speech, I hope that I wouldn't heckle and jeer throughout but would listen and quietly acknowledge the good points.
In Nuremberg, which I edited from transcripts on the 50th anniversary of the war crimes trials, Hermann Göring makes a final speech in his defence.
It is a final speech that resonates today for those of us who live in a nation that can offer the world only imperfection.
But it was later, in a final speech to House Democrats, that Mr. Obama galvanized his party by chuckling at Republican warnings that Democrats would suffer at the polls.
In any case, the city's plight, caused by the epidemic, triggered a new wave of public uproar, and Pericles was forced to defend himself in an emotional final speech, a rendition of which is presented by Thucydides.
In it, a miscast Kevin Costner playing real-life District Attorney Jim Garrison delivers an emotional final speech revealing a massive government conspiracy.
In a bitter final speech, he accused MPs of "passing up the opportunity" to clean up the expenses system last year.
In a heartbreaking final speech, just before he bolts from the scene, Darrell says, "Guess I'll just keep driving, you know?
Those who don't bring outside knowledge to the film will find themselves clueless at a rousing final speech, in which the eventual name of Dr Dre's record label is invoked.
