2010 was a great year for South Koreas, In -Kyung Kim as she recorded her third-career LPGA victory at the Lorena Ochoa Invitational by Banamex and Corona Light. The day after she won, Kim announced that she would donate her entire $225,000 first-place check to charity. Kim also finished tied for third at the RICOH Women's British Open and LPGA Tour Championship. In the same year Kim also won Rookie of the Year honors on the Ladies European Tour. She joined the LET in 2010 after winning the Dubai Ladies Masters in December 2009.

Along with her victory at the Dubai Ladies Masters, the season-ending event on the Ladies European Tour (LET), Kim won the LPGA State Farm Classic, her second LPGA victory of her career; carded a career-low in the second round of the Michelob ULTRA Open at Kingsmill, where she finished runner-up. Kim crossed the $2 million mark in career earnings at the Wegmans LPGA, where she tied for 10th.

In 2008, Kim became a Rolex First-Time Winner at the Longs Drugs Challenge, where she crossed the $1 million mark in career earnings; recorded six additional top-10 finishes, including a tie for third at the U.S. Women's Open; carded a season-low 65 in the first round of the Ginn Tribute Hosted by ANNIKA.

Kim made a strong impression in her rookie season of 2007, notching two top ten finishes including a runner-up finish at the Wegmans LPGA and a share of 4th at the LPGA Corning Classic.

Kim enjoyed a successful amateur career. She was a member of the Korean National Team in 2003 and 2004. In 2006, still as an amateur, she shared co-medalist honors at the LPGA Final Qualifying Tournament to earn exempt status for the 2007 LPGA season; and turned professional immediately following the final round.