The authors agree that the surname shows connections with the month of May, although they differ on the mechanisms of formation and on the geographical extension they attribute to it.

V. Blunda considers it a Sicilian surname of dialect origin, derived from the word majulìnu, with the meaning "born in May". According to Blunda, the diminutive took the month of birth as an identifying trait, and the surname could have originated in the label applied to the child born in that month, a usual motivation in onomastics linked to the calendar.

F. Miranda broadens the picture with other hypotheses. Besides the origin in a byname for someone born in May —attested in Sicilian as maiulinu—, Miranda proposes a toponymic origin: the surname could derive from Maiola, a hamlet of the municipality of Vetto in the province of Reggio Emilia, or from Maiolo, a municipality of Rimini, both in Emilia-Romagna. He also adds a possible connection with the term magliolo (Latin malleulus), which designates the vine shoot that is transplanted so that it may take root. Miranda documents a presence concentrated in Sicily —especially in the Messina, Syracuse, Catania and Palermo areas— with secondary cores in Calabria, Liguria, Campania, Lazio, Lombardy, Piedmont, Tuscany, Friuli-Venezia Giulia and Puglia.

The source Surnames in Italy, drawing on E. Rossoni, places the surname within a broader onomastic group that includes the variants Maiolo, Maiola, Maioli, Maiolini and Maiulini. Rossoni attributes to this group a double origin: patronymic, from the medieval personal name Maiolo or Maiolus, documented from the 12th century; and indirectly toponymic, linked to places called Maiolo or Maiola, derived from the Latin maius. For the variant Maiolino specifically, Rossoni notes a main presence in Emilia-Romagna and the Marche, with secondary cores in Umbria and Abruzzo, and local, infrequent records in the Udine area.