In the Hankook Ilbo poll, 50.1 percent of people supported Lee, compared to 38.5 percent who disapproved of his job performance.
Lee’s approval rating stood at 44.2 percent in an East Asia Institute (EAI) survey of 800 people in late November.
The EAI poll was taken days after North Korea launched the deadly bombardment of Yeonpyeong, which killed four South Koreans.
Analysts said the rebounding of Lee’s approval rating is because of his tough stance toward the North from early December.
Lee gave the green light to an artillery exercise on Yeonpyeong Island despite the international community’s worries over military tension between the two Koreas.
In a move to send a clear signal to Pyongyang, Lee stressed on several occasions Seoul’s military readiness for retaliatory strikes against the North if it committed any further provocative acts.
Meanwhile, the survey showed that Rep. Park Geun-hye of the ruling Grand National Party (GNP) was unrivaled in support for presidential hopefuls.
Support for the former GNP chairwoman was tallied at 33.5 percent, followed at a great distance by former Health and Welfare Minister Rhyu Si-min (6.3 percent) and Seoul Mayor Oh Se-hoon (5.9 percent).
Kim Moon-su, governor of Gyeonggi Province, came in fourth place with 5.4 percent and Sohn Hak-kyu, chairman of the main opposition Democratic Party, scored 4.5 percent.
Four out of 10 respondents said the government should give top priority to stabilizing inflation. Respondents also picked job creation (40.3 percent) and mutually-beneficial relations between large and small businesses (9.6 percent) and redistribution of wealth (7.3 percent) as policy priorities.
According to the survey, 57.2 percent of respondents supported an increase in social spending from the current level, while 33.2 percent wanted the current level to be maintained.
Asked which side is to blame for scuffles and melees at the National Assembly, the vast majority (72 percent) said both the ruling and opposition parties should be criticized.