The Stoics wrote about death plainly and often. For them, remembering that life ends was a way to use today well and to fear the end less. Every quote below comes from Seneca's letters, Marcus Aurelius's Meditations or Epictetus, with the book and section so you can check it yourself, in public-domain translations.
The practice behind many of these lines has its own page: memento mori. This page is for the words themselves.
Marcus Aurelius on death
Marcus wrote the Meditations as notes to himself, and death comes up in almost every book. The translation is George Long's.
"Do not act as if thou wert going to live ten thousand years. Death hangs over thee. While thou livest, while it is in thy power, be good."
Meditations 4.17
"Since it is possible that thou mayest depart from life this very moment, regulate every act and thought accordingly."
Meditations 2.11
"...remember that no man loses any other life than this which he now lives, nor lives any other than this which he now loses."
Meditations 2.14
"Thou wilt soon die, and thou art not yet simple, nor free from perturbations, nor without suspicion of being hurt by external things, nor kindly disposed towards all; nor dost thou yet place wisdom only in acting justly."
Meditations 4.37
"Severally on the occasion of everything that thou dost, pause and ask thyself if death is a dreadful thing because it deprives thee of this."
Meditations 10.29
"Do not despise death, but be well content with it, since this too is one of those things which nature wills."
Meditations 9.3
"Death is a cessation of the impressions through the senses, and of the pulling of the strings which move the appetites, and of the discursive movements of the thoughts, and of the service to the flesh."
Meditations 6.28
"Lucilla saw Verus die, and then Lucilla died. Secunda saw Maximus die, and then Secunda died. ... Such is everything."
Meditations 8.25
"When a man kisses his child, said Epictetus, he should whisper to himself, 'To-morrow perchance thou wilt die.'"
Meditations 11.34, quoting Epictetus
Most of these turn death straight back into an instruction about today: be good while it is still in your power.
Seneca on death
Seneca wrote his letters to Lucilius in the last years of his life, and death comes up again and again. The translation is Richard Mott Gummere's.
"...who understands that he is dying daily? For we are mistaken when we look forward to death; the major portion of death has already passed. Whatever years be behind us are in death's hands."
Letters 1.2
"No evil is great which is the last evil of all."
Letters 4.3
"You do not know where death awaits you; so be ready for it everywhere."
Letters 26.7
"Show me that the good in life does not depend upon life's length, but upon the use we make of it..."
Letters 49.10
"Death is non-existence, and I know already what that means. What was before me will happen again after me."
Letters 54.4
"Before I became old I tried to live well; now that I am old, I shall try to die well; but dying well means dying gladly."
Letters 61.2
"Whoever complains about the death of anyone, is complaining that he was a man. Everyone is bound by the same terms: he who is privileged to be born, is destined to die."
Letters 99.8
"Therefore, my dear Lucilius, begin at once to live, and count each separate day as a separate life."
Letters 101.10
Letter 54 is the most practical of these. Seneca had asthma, and he tells Lucilius that doctors called it "practising how to die". He used each attack to remind himself that death is only non-existence, which he had already known before he was born.
Epictetus on death
Epictetus put the fear of death where he put every fear: in our judgement of the thing. The Enchiridion is in P. E. Matheson's translation and the Discourses in W. A. Oldfather's.
"What disturbs men's minds is not events but their judgements on events: For instance, death is nothing dreadful, or else Socrates would have thought it so. No, the only dreadful thing about it is men's judgement that it is dreadful."
Enchiridion 5
"Keep before your eyes from day to day death and exile and all things that seem terrible, but death most of all, and then you will never set your thoughts on what is low and will never desire anything beyond measure."
Enchiridion 21
"What is death? A bugbear. Turn it about and learn what it is; see, it does not bite."
Discourses 2.1.17
A bugbear is a mask that frightens children because they have never looked behind it. Chapter 21 is the one to keep, and we have a longer piece on it: keep death in mind.
A popular death quote that is not Stoic
"Everybody dies, but not everybody lives" is often shared as a Marcus Aurelius quote. He did not write it, and we traced where it comes from. If a death quote has no book or letter number, check it before you share it. Our Stoic quote source audit lists the common fakes.
One way to use these
Choose one line and read it each morning for a week. Then, once during the day, ask Marcus's question from 10.29: would losing this particular thing make death dreadful? It works best on ordinary moments, like a queue or a dull meeting, because those are the hours we assume we will always get back.
If thinking about death stirs up more fear than it settles, keep it brief and come back to it another day.
Sources
Marcus Aurelius, Meditations, translated by George Long (1862): 2.11, 2.14, 4.17, 4.37, 6.28, 8.25, 9.3, 10.29 and 11.34.
Seneca, Moral Letters to Lucilius, translated by Richard Mott Gummere, Loeb Classical Library, 1917 to 1925: Letters 1, 4, 26, 49, 54, 61, 99 and 101.
Epictetus, Enchiridion, translated by P. E. Matheson (1916): chapters 5 and 21. Discourses, translated by W. A. Oldfather, Loeb Classical Library, 1925: 2.1.
If you want structured practice, the 7-Day Stoic Challenge is free. Nine audio lessons and a 42-page workbook.