Rabbi Isaac ben Mattathiah Aboab (Hebrew: רבי יצחק בן מתתיה אבוהב; d. 1720) also known as Isaac Aboab V an early 18th-century rabbinic scholar and hakam of the Portuguese congregation in Amsterdam.
His father Mattathiah Aboab was a representative of the congregation Bet Jacob.
Mattathiah was a cousin and contemporary of Isaac da Fonseca Aboab and often confounded with him.
In his early years Aboab became a friend of the learned William Surenhuysius.
Later writing a book of exhortation and admonition for his son, which appeared at Amsterdam, in 1687, under the title "Exortação Paraque os Tementes do Senhor na Observança dos Preceitos de sua S.