Joab's Family
Zeruiah - Joab's mother and King David's sister.
Abishai - Joab's brother and fellow military commander under David.
Asahel - Joab's youngest brother, killed by Abner in battle.
Amasa - Joab's cousin and briefly David's military commander; Joab killed him out of jealousy.
Saul's Family
David - King of Israel and Joab's uncle; Joab served as his military commander.
David's Family
Bathsheba - Solomon's mother; her rise to prominence affected the political landscape Joab operated in.
Adonijah - David's son who attempted to claim the throne; Joab supported his bid for kingship.
Absalom - David's son; Joab killed him during his rebellion against David.
Jonadab - David's nephew; he was present during some of the family conflicts Joab was involved in.
Abishag - David's young attendant (not actually a wife or concubine); her presence indirectly affected the political situation Joab navigated.
Abishag cared for the elderly King David. After David's death, his son, Adonijah asked to marry her (1 Kings 2:13-22). Adonijah, supported by Joab, had earlier attempted to seize the thrown, in competition with Solomon (1 Kings 1:1-10). Solomon saw the marriage request as treasonous (1 Kings 2:22) and used it as an opportunity to order the deaths of both Adonijah and Joab at the hands of Benaiah (1 Kings 2:13-35)
Military commanders and soldiers
Saul's army
Abner - Commander of Saul's army, killed by Joab in revenge for Asahel's death.
David's army
Uriah the Hittite - One of David's soldiers; Joab followed David's orders to have him killed in battle.
Benaiah - Commander of David's bodyguard; he carried out Solomon's order to execute Joab.
Ittai the Gittite - A loyal follower of David; he fought alongside Joab in various battles.
Priests
Zadok - High Priest during David's reign; he interacted with Joab during various political events.
Abiathar - Another priest during David's time; he was involved in some of the same events as Joab.
Prophets
Nathan - Prophet during David's reign; his prophecies and advice influenced events Joab was involved in.
Sheba - A Benjamite rebel; Joab pursued and defeated him.
Rechab and Baanah - Assassins of Ish-bosheth; Joab's actions were indirectly affected by their deed.
Hushai the Arkite - David's friend and spy; he worked with Joab to thwart Absalom's rebellion.
Ahithophel - David's advisor who joined Absalom's rebellion; Joab's strategies countered his advice.
Shimei - A Benjamite who cursed David; Joab was present when David dealt with him.
The wise woman of Abel Beth Maacah - She negotiated with Joab during the siege of her city.
Rizpah - Saul's concubine; her devotion to her sons led to Joab's assassination.