Will getting a signature loan to pay off one of your credit card balances lower your credit score?

Elaborating on the below answer, yes possibly initially for a month or two; just the length of time it would take for the credit card to report a zero balance to offset the "installment" loan (signature loan). Installment loans are looked upon more favorably than revolving debt of a credit card. Suggestion, though, if you have had the credit card opened for quite some time, I would not recommend closing it. Accounts that are open the longest and have the lowest balances help your score rating more favorably than your closing it altogether. Initially yes, it could.