The Korea Composite Stock Price Index (KOSPI) rose 0.5 percent to close at 1,997.05 points, a one-week high.
"It's worth noting that the index was able to sustain the gains made in September on global monetary easing and in November from the relief that China was not heading for a hard-landing," said Han Beom-ho, an analyst at Shinhan Investment Corp.
"Heading into the new year, a bargain to avert a US fiscal crisis and the earnings of local companies will be the key factors to watch for."
Monetary easing from the United States and Europe in September lifted the KOSPI, which had been rattled by the euro zone's debt woes. But expectations of Japan's further monetary easing bode ill for South Korean exporters because a softer yen improves the price competitiveness of Japanese rivals.
Hyundai Motor and Kia Motors fell to their lowest levels in more than one month as the won's value against the yen headed for the fastest annual gain since 1998, according to Reuters data.
However, Samsung Electronics, which accounts for around a fifth of the KOSPI's market value, ended up 1.7 percent to reach its second-highest closing price of 1,522,000 Korean won ($1,400).
Trading volumes were the lowest in a month, and investors were left wondering whether the incoming South Korean government will implement more fiscal and monetary stimulus to bolster the export-reliant economy.
Local institutions bought a net 181 billion won ($168.82 million) worth of KOSPI shares, insulating the index from foreign and retail selling.
The KOSPI 200 benchmark of core stocks closed up 0.5 percent, while the junior KOSDAQ edged 0.9 percent higher.
South Korean markets will reopen on Tuesday, Jan. 2 at 10 a.m. (GMT +9), one hour later than usual after a brief opening ceremony to ring in the new year.