To configure Log4j for logging in to a Spring Boot application, you must include the Log4j dependency in your project's build configuration (e.g., pom.xml for Maven). Then, create a Log4j configuration file (e.g., log4j2.xml or log4j.properties) to specify logging levels, appenders, and other settings. Place this configuration file in the classpath of your application, and Log4j will automatically use it for logging.