Not Really
Paying off old debts does nothing to improve your credit score. It does however look much better to new creditors that you don’t have any outstanding delinquent accounts with balance on your report.
The only way you CAN improve your credit score is with a Pay-For-Delete agreement, but these are hard to get, and you’ll probably need to pay the debt in full.
Never the less, you should pay off your debt. Here’s why.