The following is a guide for properly addressing Orthodox clergy. Most of the titles do not exactly correspond to the terms used in Greek, Russian or other native languages of various national Orthodox Churches, but they have been widely accepted for standard English usage.
Greeting Clergy in Person
When we address Deacons or Priests, we should use the title "Father". We should address bishops as "Your Grace". Though all bishops (including patriarchs) are equal in the Orthodox Church, they do have different administrative duties and honors that accrue to their rank in this sense. Thus, "Your Eminence" is the proper title for bishops with suffragans or assistant bishops; Metropolitans and most Archbishops … - "Your Beatitude" is the proper title for patriarchs (except for the Œcumenical Patriarch in Constantinople, who is addressed as "Your All-Holiness"). When we approach an Orthodox Presbyter or Bishop (but not a deacon), we make a bow by reaching down and touching the floor with our right hand, place our right hand over the left (palms upward) and say: "Bless, Father" (or "Bless, Your Grace" or "Bless, Your Eminence", etc.). The priest or bishop then answers, "May the Lord bless you" as he blesses us with the Sign of the Cross, and places his right hand in our hands. We then kiss his hand.
We should understand that when the priest or bishop blesses us, he forms his fingers to represent the Christogram "ICXC", a traditional abbreviation of the Greek words for "Jesus Christ" (i.e., the first and last letters of each of the words "IHCOYC XRICTOC"). Thus, the priest's blessing is in the name of Christ, as he emphasizes in his response to the believer's request for a blessing. Other responses to this request are used by many clergy, but the antiquity and symbolism of the tradition, which we have presented, are compelling arguments for its use. We should also note the reason for a lay person kissing the hand of a priest or bishop is to show respect to his apostolic office. More importantly, however, since both hold the Holy Mysteries in their hands during the Divine Liturgy, we show respect to the Holy Eucharist when we kiss their hands. In fact, Saint John Chrysostomos once said that if one were to meet an Orthodox priest walking along with an angel, that he should greet the priest first and kiss his hand, since that hand has touched the Body and Blood of our Lord. For this latter reason, we do not normally kiss the hand of a deacon. While a deacon in the Orthodox Church holds the first level of the priesthood (deacon, presbyter, bishop), his service does not entail blessing the Mysteries. - When we take leave of a priest or bishop, we should again ask for a blessing, just as we did when we first greeted him.
In the case of married clergy, the wife of a priest or deacon is also informally addressed with a title. Since the Mystery of Marriage binds a Priest and his wife together as "one flesh", the wife shares in a sense her husband's priesthood. This does not constitute of course that she has the very grace of the priesthood or its office; but the dignity of her husband's service certainly accrues to her. The various titles used by the national churches are listed below. The Greek titles, since they have English correspondents, are perhaps the easiest to remember here in the West:
Greek: Presbytera (Pres—vee—té—ra)
Russian: Matushka (Má—toosh—ka)
Serbian: Papadiya (Pa—pá—dee—ya)
Ukrainian: Panimatushka (Pa—nee—má—toosh—ka) or Panimatka (Pa—nee—mát—ka)
The wife of a deacon is called "Diakonissa" [Dee-a-kó-nees-sa] in Greek. The Slavic Churches commonly use the same title for the wife of a deacon as they do for the wife of a priest. In any case, the wife of a priest should normally be addressed with both her title and her name in informal situations (e.g., "Presbytera Mary", "Diakonissa Sophia", etc.).
Greeting Clergy on the Telephone. Whenever you speak to Orthodox clergy of priestly rank on the telephone, you should always begin your conversation by asking for a blessing: "Father, bless". When speaking with a bishop, you should say "Bless, Despota [Thés—po—ta]" (or "Vladika [Vlá—dee—ka]" in Slavonic, "Master" in English). It is also appropriate to say, "Bless, Your Grace" (or "Your Eminence," etc.). You should end your conversation by asking for a blessing again.
Addressing Clergy in Correspondence
When we write to a clergyman (and, by custom, monastics), we should open our letter with the greeting, "Bless, Father". At the end of the letter, it is customary to close with the following line: "Kissing your right hand...." It is not appropriate to invoke a blessing on a clergyman, as many do: "May God bless you". Not only does this show a certain spiritual arrogance before the image of the cleric, but laymen do not have the grace of the priesthood and the prerogative to bless in their stead. Even a priest properly introduces his letters with the words, "The blessing of the Lord" or "May God bless you", rather than offering his own blessing. Though he can do the latter, humility prevails in his behavior, too. Needless to say, when a clergyman writes to his ecclesiastical superior, he should ask for a blessing and not bestow one.
Formal Address. Deacons in the Orthodox Church are addressed as "The Reverend Deacon", if they are married deacons. If they are deacons who are also monks, they are addressed as "The Reverend Hierodeacon". If a deacon holds the honor of Archdeacon or Protodeacon, he is addressed as "The Reverend Archdeacon" or "The Reverend Protodeacon". Deacons hold a rank in the priesthood and are therefore not laymen ... As members of the priesthood, deacons must be addressed as "Father Deacon".
Orthodox priests are addressed as "The Reverend Father, if they are married priests. If they are Hieromonks (monks who are also priests), they are addressed as "The Reverend Hieromonk". Priests with special honors are addressed in this manner: an Archimandrite (the highest monastic rank below that of Bishop), "The Very Reverend Archimandrite" (or, in the Slavic jurisdictions, "The Right Reverend Archimandrite"); and Proto-presbyters: "The Very Reverend Protopresbyter". In personal addressing, as we noted above, all priests are called "Father", usually followed by their first names (e.g., "Father John").
Bishops in the Orthodox Church are addressed as "The Right Reverend Bishop", followed by their first name (e.g., "The Right Reverend Bishop John"). Archbishops, Metropolitans and Patriarchs are addressed as "The Most Reverend Archbishop" ("Metropolitan" or "Patriarch"), because they are usually monastics, all ranks of Archpastors (Bishops, Archbishops, Metropolitans or Patriarchs) are addressed by their first name or and See (e.g., "Bishop John of San Francisco"). It is not correct to use the family name of a bishop — or any monastic for that matter. Though many monastics and bishops use their family name, even in Orthodox countries like Russia and Greece, this is absolutely improper and against ancient custom.
All male monastics in the Orthodox Church are called "Father", whether they hold the priesthood or not, and are formally addressed as "Monk (name)", if they do not have a priestly rank. If they are of priestly rank, they are formally addressed as "Hieromonk" or "Hierodeacon" (see above). Monastics are sometimes addressed according to their monastic rank; for example, "Rasophore-monk (name)", "Stavrophore-monk (name)", or "Schemamonk (name)". The Abbot of a monastery is addressed as "The Very Reverend Abbot", whether or not he holds priestly rank and whether or not he is an Archimandrite by rank. Under no circumstances whatsoever is an Orthodox monk addressed by laymen as "Brother". This is a Latin custom. The term "Brother" is used in Orthodox monasteries in two instances only: first, to designate beginners in the monastic life (novices or, in Greek, dokimoi ["those being tested"]), who are given a blessing, in the strictest tradition, to wear only the inner cassock and a monastic cap; and second, as an occasional, informal form of address between monastics themselves (including bishops).
Again, as we noted above, a monk should never use his last name. This reflects the Orthodox understanding of monasticism, in which the monastic dies to his former self and abandons all that identified him in the world. Lay people are also called to respect a monk's death to his past. (In Greek practice, a monk sometimes forms a new last name from the name of his monastery. Thus a monk from the Saint Gregory Palamas Monastery [Mone Agiou Gregoriou Palama, in Greek] may take the name Agiogregorites.)
The titles which we have used for male monastics also apply to female monastics. In fact, a community of female monastics is called a "monastery" as well, rather than the rather catholic term "convent" in America. Women monastics are formally addressed as "Nun (name)" or "Rasophore-nun (name)", etc., and the Abbess of a monastery is addressed as "The Very Reverend Abbess". Though traditions for informal address may vary, in most places Rasophore nuns are called "Sister", while any monastic above the rank of Rasophore is called "Mother". Novices are always addressed as "Sister".
There are, as we have noted, some differences in the way that Orthodox religious are addressed. What we have given above corresponds to a reasonably standardized vocabulary as one would find it in more traditional English-language Orthodox writings and among English-speaking Orthodox monastics …
(Adapted from from Fr. David Cownie and Presbytera Juliana Cownie, A Guide to Orthodox Life)