This qualitative study explores the supportive strategies used by formal caregivers when interacting with Deaf people with dementia. The data consist of video-recorded interactions between dyads of nine caregivers and five Deaf participants in a nursing home for the Deaf in Finland. We analyzed 21 interactions (5 hours and 25 minutes in total), using two methods: inductive content analysis and the Interactive Coping Behavior Coding System. The study found that the formal caregivers used a wide range of supportive strategies. We identified five strategies: (1) interaction maintenance, (2) emotional support, (3) instrumental support, (4) informational support, and (5) memory support. The formal caregivers also used dismiss and avoidance behaviors when the interaction became challenging. Nonproficiency in sign language hindered support. In the future, attention should be paid to teaching formal caregivers national sign language and supportive communication competence for working with Deaf people with dementia.