ethicist

[ eth-uh-sist ]
/ ˈɛθ ə sɪst /

noun

a person who specializes in or writes on ethics or who is devoted to ethical principles.
Also e·thi·cian [e-thish-uh n] /ɛˈθɪʃ ən/.

Origin of ethicist

First recorded in 1890–95; ethic + -ist