Sebastian Pinera won Chile's presidential run-off election on Sunday, defeating centre-left senator Alejandro Guillier by 54.6% to 45.4%.
Guillier conceded a "severe defeat" defeat to his supporters as the result came in, while outgoing president Michelle Bachelet called Pinera to offer congratulations.
Pinera supporters celebrated at his campaign headquarters and many took to streets nationwide waving flags and holding banners.
Pinera, 68, a former airline magnate who previously governed Chile in 2010-2014, said: "Today the voice of all Chileans has been heard. We welcome this triumph with humility and hope."
Many Chileans have been disillusioned by lagging economic growth under the Bachelet's administration, a product of lower international prices for copper, the backbone of Chile's economy.
Former TV anchor Guillier had vowed to continue Bachelet's plan to increase corporate taxes to partly finance an education overhaul, reform the constitution and improve the pension and health care system.
During his first term as president, Pinera struggled with large protests over Chile's inequality and demands for education reform, and left office with low popularity ratings. But he also oversaw annual economic growth of about 5% a year.
The conservative politician now proposes to slash taxes on business to revive growth and vows to launch a 14 billion dollar (£10.5 billion), four-year spending plan that includes fresh investments in infrastructure.
"This is a huge victory for him," said Javier Sajuria, a lecturer in politics at Queen Mary University of London. "Pinera managed to gather a big majority of the votes from centre-left candidates (in the first round of the election). What happened here is that Pinera managed to mobilise non-voters in a way that we haven't seen since voluntary voting was started."
Turnout was expected to be low because in contrast to other regional countries, Chile made voting voluntary rather than mandatory in 2012.