Presidential elections in Singapore, in which the President of Singapore is directly elected by popular vote, were introduced through amendments to the Constitution of Singapore in 1991. Potential candidates for office have to fulfil stringent qualifications set out in the Constitution. Certificates of eligibility are issued by the Presidential Elections Committee (PEC). In particular, the PEC must assess that they are persons of integrity, good character and reputation; and if they have not previously held certain key government appointments or acted as chairman of the board of directors or chief executive officer of a company incorporated or registered under the Companies Act (Cap. 50, 2006 Rev. Ed.) with a paid-up capital of at least S$100 million, they must demonstrate to the PEC that they held a position of comparable seniority and responsibility in the public or private sector that has given them experience and ability in administering and managing financial affairs. The strictness of these qualifications led to the 1999 and 2005 elections being walkovers as only one candidate, S.R. Nathan, received a certificate of eligibility from the PEC. The stringent criteria, the transparency of the PEC's decision-making process and the practice of political parties endorsing candidates have drawn criticism.
The office of President falls vacant upon the expiry of the incumbent's six-year term or if the President is for some reason unable to complete his or her term; for example, due to death, resignation or removal from office for misconduct or mental or physical infirmity. If the office of President becomes vacant before the incumbent's term expires, a poll for an election must be held within six months. In other cases, an election can take place any time from three months before the expiry of the incumbent's term of office.