One in six community-dwelling older adults experience elder abuse yearly, and persons with dementia are especially at risk. Although many risk factors for elder abuse have been identified, there are still knowledge gaps concerning risk and protective factors. This cross-sectional survey among Norwegian informal caregivers (ICGs) aimed to find individual, relational, and community factors associated with psychological and physical abuse of home-dwelling persons with dementia. This study involved 540 ICGs and was conducted from May to December 2021. Statistical analysis using penalized logistic regression with lasso was performed to find covariates associated with psychological and physical elder abuse. The most prominent risk factor for both subtypes of abuse was the caregiver being a spouse. In addition, risk factors for psychological abuse were having a higher caregiver burden, experiencing psychological aggression from the person with dementia, and the person with dementia being followed up by their general practitioner. For physical abuse, the protective factors were the ICG being female and having an assigned personal municipal health service contact, while the risk factors were the ICG attending a caregiver training program and experiencing physical aggression from the person with dementia and the person with dementia having a higher degree of disability. These findings add to the existing knowledge of risk and protective factors in elder abuse among home-dwelling persons with dementia. This study provides relevant knowledge for healthcare personnel working with persons with dementia and their caregivers and for the development of interventions to prevent elder abuse.