Yes, you can look up another person's credit report and score without his or her knowledge. This is done all the time in today's computer online age. For example, there are many companies online that offer a service for a certain amount where they can do a background check of a specific person provided they have the person's name, date of birth, area of residence and the like.The report generated can show a credit score, asset list, lawsuits filed and bankruptcies. As such, you can hire a company to do a background check of your spouse including a credit report score on him or her.