The last words of the Roman dictator Julius Caesar are disputed. Ancient chroniclers reported a variety of phrases and post-classical writers have elaborated on the phrases and their interpretation.^[1] The two most common theories – prevalent as early as the second century AD – are that he said nothing or that he said, in Greek, καὶ σύ, τέκνον (kaì sý, téknon; 'you too, child').^[2][3]

William Shakespeare's Latin rendition of this phrase, Et tu, Brute? ('You too, Brutus?'), in the play Julius Caesar, is better known in modern culture, but is not found in ancient sources.^[4]

There has existed discourse over the likelihood of Caesar being able to say much after being stabbed, let alone something very personal and profound to Brutus, considering his age and the stress forced on him during the ordeal.^[24] The ancient historian Cassius Dio says that Caesar did not and in fact could not say or do anything, because he was mobbed. Historical biographer Stephen Spignesi on the other hand states in his book In the Crosshairs: Famous Assassinations and Attempts from Julius Caesar to John Lennon that he believes it makes sense that Caesar would at least have said something during his final moments rather than staying silent. He also states that in his opinion Caesar using the terms "child" or "son" would be in character for the man, partly as Caesar had been a longtime partner of Brutus' mother and partly because it is diminutive.^[3]

Åke Persson of Språktidningen [sv] (Swedish: The Language Magazine) expresses that there was already an expectation in ancient times that Caesar would have said something. This being due to people having a hard time accepting that a man such as him, a great spokesman and larger than life personality, would leave no final words to be remembered.^[4]

In 2014, The History Channel released a short documentary titled Coroner Report: Julius Caesar as part of their Coroner's Report series which examined if it was likely that Caesar was able to say anything at all while his attack was ongoing. The thesis for it reads "The Roman leader Julius Caesar was stabbed 23 times by a mob of mutinous senators in 44 B.C. Could he possibly have survived long enough to utter his famous last words?"^[25] The doctor postulates in the film that considering the injuries Caesar received, 23 stab wounds with the single one in the side of the chest being the only fatal one,^[26] that it is likely that he lingered on alive for a long time, possibly hours and could have very well spoken to some extent during that time. He adds that it would also depend on the exact cause of death, depending on if he died of a collapsed lung or internal bleeding, with the bleeding being more likely to leave him able to speak for longer.^[27] Since most of the cuts were inflicted one and one after another, not simultaneously (and especially since his autopsy stated that 22 out of the gashes were superficial) his body would have withdrawn blood from periphery places to try to ensure that the vital organs survived (such as brain, lungs and liver), resulting in a slow, adrenaline-filled and most importantly conscious demise.^{[28][page needed]}

The phrase "Et tu, Brute?" which was used by William Shakespeare in his famous play Julius Caesar as part of Caesar's death scene has become synonymous with betrayal in modern times due to the play's popularity and influence; this has led to the popular belief that the words were Caesar's last words.^[29] Even in the play itself the words are not Caesar's last, as he exclaims "Then fall, Caesar" afterwards before he finally dies.^[12] Despite this the words have become popularly used as his last words in media which adapts Caesar's life or that period in time. There have been a few notable exceptions to this, such as the video game Assassin's Creed: Origins which in English uses the words "You too, my child?",^[30] taken from the Greek "Kaì sú, téknon", while the French dub of the game, instead of simply translating it to French, decided to use the continental Latin translation "Tu quoque mi fili?" (You too, my son?).^[31]

In the 1964 British comedy film Carry On Cleo, before being assassinated Caesar declares "Infamy, infamy, they've all got it in for me."^[32] In 2007, the line was voted the best one-liner in a Sky Movies poll of 1,000 film fans.^[33][34]

• List of last words