Pinera, a 60-year-old billionaire, had garnered 51.6 percent of the vote to ruling coalition candidate Eduardo Frei's 48.3 percent with 99 percent of polling places reporting, The Wall Street Journal reported.
Frei, a former president who conceded defeat Sunday evening, noted his center-left Concertacion coalition had overseen Chile's transition from a dictatorship to a democracy.
"Chile is much better than the country we received in 1990," he said.
Pinera's four-year term begins in March, when he succeeds the popular President Michelle Bachelet, who was forbidden by the constitution to serve consecutive terms.
The Harvard-trained Pinera has interests in Chile's biggest airline, a soccer club and a television station. He pledged to be an "entrepreneurial president" and strive for more efficiency in the government while stimulating private investment.
Riordan Roett, a Latin America scholar at Johns Hopkins University in Baltimore, said Piñera's victory represented "the arrival in power of the democratic right that has traveled a long road from pseudo-fascism to mainstream politics."