In her speech, Haley also appeared to take aim at Trump’s inflammatory rhetoric.
The decision will ensure that Donald Trump will win the Republican nomination and once again face Democratic President Joe Biden in November's election.
Voters in 15 states and one US territory were casting ballots for president on Super Tuesday, with polls scheduled to close throughout the evening until Alaska wraps up the day.
The Super Tuesday results in North Carolina will be closely watched for signs of each candidate's strength in one of the potential battleground states that could decide the November general election.
The win, mostly seen as symbolic, inoculates Haley from criticisms that she is unable to win a single primary race, though she still faces near-impossible odds to win the Republican nomination.
Trump won the primary convincingly on Tuesday, securing 12 of 16 delegates up for grabs. He took all of Michigan's remaining 39 delegates at stake on Saturday.
Trump's victory on Saturday was not a complete blowout but he still defeated Haley by a comfortable 20 percentage points on her home turf.
Haley had hoped that South Carolina's "open" primary would lead to turnout among independents, and some Democrats who are determined to stop Trump
Haley's husband, Michael, is currently serving in a voluntary deployment in Africa.