"Visits to other parts of the world often get more attention, because I think it's kind of taken for granted in a way that we're going to be going back and forth across the Atlantic," Clinton told a Washington forum on Thursday.
"But indeed, 38 visits to Europe is something that I have been delighted to do because of the importance we place on these relationships."
Her six-day trip will see her visit Prague for meetings with Czech officials, take part in the Nato foreign ministers meeting in Brussels and then fly to Dublin for a meeting of the Organisation for Security and Co-operation in Europe. One of the issues likely to be discussed at Nato is whether to agree to Turkey's request to deploy US-made Patriot missiles along its border with Syria.
Military sources in Turkey have said Nato is considering the deployment of up to six Patriot batteries and some 300 foreign troops to operate the missiles.
The US-made missiles would likely be supplied by Germany, The Netherlands or the United States. Clinton will also visit Belfast in Northern Ireland for meetings with top ministers before flying home on Friday.
Speaking at The Brookings Institution, she said the world was counting on European leaders to meet tough economic challenges ahead and offered assurances that the United States was not turning its back on old alliances.