Peanut butter — Food safety facts
Feed with care · Dogs · full breakdown on the linked food page
Safe only if xylitol-free (many brands now add it — xylitol is fatal to dogs). High fat and salt — small amounts.
Short answer
Yes, with one big warning: many peanut butters are sweetened with xylitol, which is deadly to dogs. Always read the label first. Xylitol-free peanut butter is safe in small amounts as a treat, but it is high in fat and calories, so keep portions small and occasional.