A Christian Science practitioner is an individual who devotes their full time to the practice of healing through prayer according to the teachings of Christian Science. This usually takes the form of what is called Christian Science treatment, a systematized form of prayer involving the affirmation of absolute spiritual or metaphysical Truth of the spiritual perfection of God, and by extension, man in His image and likeness.

Mary Baker Eddy, the founder of Christian Science, was thus in effect the first practitioner of Christian Science, but her third husband, Asa Gilbert Eddy, was the first to publicly advertise himself as such.

Practitioners historically advertised as a matter of practice in the Christian Science Journal, though advertising is not mandatory, and some came to decline to do so subsequent to the church's controversial publication in 1991 of a book by Bliss Knapp. Others for various reasons have always practiced independently.

Some medical plans cover the cost of treatment received from a Christian Science practitioner listed in the Christian Science Journal as a covered medical expense.