As the older adult population rise globally, technologies to monitoring activities of daily living (ADL) may have a role in supporting aging in place for older adults. The objective of this systematic literature review was to study the scope, diversity and readiness of technologies developed to monitor ADL in older adults. We systematically searched two scientific databases (CINAHL and IEEE), following Preferred Reporting Items for Systematic reviews and Meta Analyses (PRISMA) guidelines. We included studies on technologies used to monitor older adults' ADL in the home but excluded studies focused on communication technologies (phone calls, text messages) or monitoring postures alone. The JBI checklist for case series was used for quality assessment. Extracted details included population characteristics, ADL assessment outcomes, types of monitoring technology, and technology readiness and usability. The search found 147 papers, with 16 papers included in the final analysis. The literature described 48 types of technologies. Of moderate quality studies, five studies used wearables at technology readiness level 4-6 to monitor basic ADL (walking, transfers and walking up stairs) and one used ambient sensors to detect urinary incontinence. Monitoring technologies remain at development stages. More research is needed to strengthen technologies that monitor activities of daily living.