Yes, especially when you're using a card that waives foreign transaction fees.
When traveling outside the United States, you'll almost always get the best possible exchange rate by using a major credit card with a hotel, airline or vendor. In addition, you're avoiding ATM surcharges, cash advance fees, and the infamous surcharges at most exchange desks.
Visa, MasterCard, American Express, and Discover all process foreign currency transactions on behalf of their issuing banks. Although the exchange rate you see on your statement may be slightly higher than "interbank" rates you see posted on global currency markets, they're the best rates you're likely to find as a consumer. You can see current exchange rates for select brands on their websites:
Keep in mind that the rate you'll pay gets locked in when your transaction settles, not at the time you swipe or scan your card. During periods of high exchange rate volatility, you might see a slightly different charge on your statement, compared to what you thought it would be at the time of purchase.
Most credit cards tack on their own foreign transaction fees, which usually range between 3 and 5 percent of each purchase. However, Capital One, Discover, and Pentagon Federal Credit Union don't charge those fees on cards they issue. Chase, American Express, and a handful of other banks waive their fees on certain travel rewards cards and premium accounts.
Regardless of which card you choose to carry outside the country, watch out for a "convenient" service that's becoming common in tourist-heavy cities around the world. Some merchants may ask you if you prefer to process your transactions in dollars instead of the local currency. While this option sounds helpful, the merchant's bank typically applies an inflated conversion rate that could cost you more than if you had made a cash advance at an ATM. Stick to processing your purchases in your vendors' native currency, and your payment platform will handle the rest.