A series of surnames share the root mass- (from the Latin massa, "mass" or "body of lands"), but their history and origin branch into two clearly distinct lines.

• Massa and its toponymic derivatives —such as Massascusa, Massagrande or Massazza— refer back to the place itself: these are names born from old "masses" or rural holdings, from those agrarian estates which in the Middle Ages gave rise to inhabited settlements.
• Massaro and its variants —Massari, Massara, Massarotti, Massaren(t)e, Ammassari, and so on— come from the trade: they were the stewards or bailiffs of those same estates (massarie), trusted figures who were identified by their office.

Thus, although etymologically related in the idea of "cultivated land", Massa points to the place and Massaro to the person who manages it.

Surnames from the trade of massaro (bailiff / steward of estates)

These derive from the Latin massarius → Italian massaro, "he who manages the massaria".

• Massari / Massaro
• Ammassari (with a prosthetic "A-"). Prosthesis is a linguistic phenomenon by which a sound (often a vowel) is added at the beginning of a word to make it easier to pronounce. In Ammassari, a prosthetic vowel (the "A") has historically been added before the stem massari. In many dialects of southern Italy a vowel is placed before initial consonant clusters to ease pronunciation. Ammassari is therefore not a different trade, but simply the dialect variant of Massari in which an initial A- is attached without altering the meaning: it still means "the bailiff or steward of the massaria".
• Massara (in Lombardy; and in Calabria it mixes with the place name Mazara)
• Strict variants and derivatives of this group:
  • Massarelli / Massarello / Massarenti / Massarente
  • Massarotti / Massarotto
  • Massarutti / Massarini / Massarino
  • Masseri / Massera / Masser / Massero
  • Massariol (a dialect diminutive, "little massaro")

Toponymic surnames (places called "Massa…" and the like)

These arose from the name of a place ("Massa", Massa Marittima, Massascusa, Massazza…):

• Massagrande (from the dialect nickname massa grande)
• Massascusa (from Massascusa, in the Salerno area)
• Massazza (from Massazza, Biella)
• Massara (in its Calabrian strand, from Mazara)

Nicknames, dialect forms and augmentatives

These are born from local nicknames, affective suffixes or errors of spelling:

• Massasogni (possibly from the Lombard appellative massa caìco)
• Massaron, Massarone, Massaroni, Massarroni, Massirone, Messironi (augmentatives or spelling variants)
• Massanti (from massa, "mace" → blacksmith, carpenter)
• Massi / Masso (dialect developments, sometimes through confusion with Mazzo)

Although they all begin with Mass-, Massolo and Massola have an origin different from that of the occupational surnames (Massaro, Massari and the like) and they also differ from the toponymic surnames and from those derived from Mazza.

Related and derived surnames

Ammassari, Massa, Massanti, Massara, Massarelli, Massarello, Massari, Massariol, Massarente, Massarenti, Massarini, Massarino, Massarotti, Massarotto, Massarutti, Masseri, Massera, Masser, Massero, Massasogni, Massaro, Massagrande, Massascusa, Massazza, Massaron, Massarone, Massaroni, Massarroni, Massirone, Messironi, Massi, Masso.