No.  It won’t ruin your credit, and unless you are 30 days or more late, the late payment will not even show up on your credit report.  That being said, this is a very bad habit to get into, so make sure you don’t do it again.  Even if you are just one day late, your credit card company will assess a late fee on your account.  If you are more than 30 days late, your credit card company will report you to the credit bureaus and this one late payment will stay on your credit report for seven years, even though it will only have a marginal impact on your actual credit score after the first couple of years.  The bottom line is that you should everything you can to pay your credit card bill on time EVERY time.