最後だ

This is the last one.

→ 最後
phrase Common #7,905
This is the last one. Says that something is last in order or that this is the final occasion. The plain form; だ is casual.
JA: この曲が最後だ。
EN: This is the last song.

何度も人を襲ってきたが、今度が本当に最後だな。

I've attacked people time and time again, but this really will be the last time.

これで最後だ。

This is the last one.

デカを殴ったのはあれが最後だ

That was the last time I punched a cop.

— ワンス・アポン・ア・タイム・イン・ハリウッド (2019)

もう会えないからさ、今日が最後だ、

Because we won't be able to see each other again, today is the last time.

— ベイビー・ブローカー (2022)

もう少しこいつをそれが最後だ

Just a little more of this guy, and that’s the last one.

— マルコムX (1992)

頼み事はこれで最後だよ。

This is the last favor I'm asking.

分った最後だぞ有難うございます

Got it. This is the last one, okay? Thank you very much.

— 帰ってきたヒトラー (2015)

この曲が最後だ

This is the last song.

— ベルリン・天使の詩 (1987)

それで最後だ!

And that's the last of it!

これで最後だよ。

This is the last one.

それが最後だ

That's the last one.

— 惑星ソラリス (1972)

トムは列の最後だ。

Tom is at the end of the line.

そういう冒険ができるのも今が最後だ

This may be my last chance to go on an adventure like that.

— フィールド・オブ・ドリームス (1989)