Contemporary Writers, even those less sympathetic to the king, agreed that Richard was a "most beautiful king", though with a "face which was white, rounded and feminine", implying he lacked manliness. He was athletic and tall; when his tomb was opened in 1871 he was found to be six feet tall. He was also intelligent and well read, and when agitated he had a tendency to stammer. While the Westminster Abbey portrait probably shows a good similarity of the king, the Wilton Diptych portrays the king as significantly younger than he was at the time; it must be assumed that he had a beard by this point. Religiously, he was orthodox, and particularly towards the end of his reign he became a strong opponent of the Lollard heresy. He was particularly devoted to the cult of Edward the Confessor, and around 1395 he had his own coat of arms impaled with the mythical arms of the Confessor. Though not a warrior king like his grandfather, Richard nevertheless enjoyed tournaments, as well as hunting.

Richard's mental state has been a major issue of historical debate since the first academic historians started treating the subject in the 19th century. One of the first modern historians to deal with Richard II as a king and as a person was Bishop Stubbs. Stubbs argued that towards the end of his reign, Richard's mind "was losing its balance altogether". Historian Anthony Steel, who wrote a full-scale biography of the king in 1941, took a psychiatric approach to the issue, and concluded that the king had schizophrenia. This was challenged by V. H. Galbraith, who argued that there was no historical basis for such a diagnosis, a line that has also been followed by later historians of the period, such as Anthony Goodman and Anthony Tuck. Nigel Saul, who wrote the most recent academic biography on Richard II, concedes that – even though there is no basis for assuming the king had a mental illness – he showed clear signs of a narcissistic personality, and towards the end of his reign "Richard's grasp on reality was becoming weaker".

Rumours that Richard was still alive persisted, but never gained much credence in England; in Scotland, however, a man identified as Richard came into the hands of Regent Albany, lodged in Stirling Castle, and serving as the notional – and perhaps reluctant – figurehead of various anti-Lancastrian and Lollard intrigues in England. Henry IV's government dismissed him as an impostor, and several sources from both sides of the Border suggest the man had a mental illness, one also describing him as a "beggar" by the time of his death in 1419, but he was buried as a king in the local Dominican friary in Stirling. Meanwhile, in 1413, Henry V – in an effort both to atone for his father's act of murder and to silence the rumours of Richard's survival – had decided to have the body at King's Langley moved to its final resting place in Westminster Abbey. Here Richard himself had prepared an elaborate tomb, where the remains of his wife Anne were already entombed.

Richard's posthumous reputation has been shaped to a large extent by william Shakespeare, whose play Richard II portrayed Richard's misrule and his deposition by Bolingbroke as responsible for the 15th-century Wars of the Roses. Modern historians do not accept this interpretation, while not exonerating Richard from responsibility for his own deposition. While probably not insane, as historians of the 19th and 20th centuries believed, he may have had what Psychologists today identify as a personality disorder, particularly manifesting itself towards the end of his reign. Most authorities agree that, even though his policies were not unprecedented or entirely unrealistic, the way in which he carried them out was unacceptable to the political establishment, and this led to his downfall.