The International Classification of Diseases-11th Edition (ICD-11) includes a dimensional trait model of personality disorder. The Personality Inventory for ICD-11 (PiCD) was the first self-report measure developed for its assessment. The present study examines the validity of an informant-report version of the PiCD, the Informant-Personality Inventory for ICD-11 (the IPiC), and is the first study to test self-other agreement, ratings from close others, and the criterion validity of both the IPiC and the PiCD for several popular and well-validated measures of life functioning: Life and romantic relationship satisfaction, social support, physical and mental health, depressive symptoms, insomnia symptoms, and cognitive decline. The present study is also the first to examine the IPiC and PiCD in a sample of older adults in the community. Results suggest that the IPiC and the PiCD show moderate self-other agreement, are associated significantly with several important life functioning areas, and have structural validity even at the item level. Further replication and validation are necessary for these instruments, but the IPiC and the PiCD have shown strong validation evidence to date, now including evidence of consensual and criterion validity, in addition to structural validity. (PsycInfo Database Record (c) 2021 APA, all rights reserved).