The Red Devils said both players had signed five-year contracts that will keep them at the club until the summer of 2031.
Abdallah, 23, enjoyed an impressive campaign with Enppi last season, scoring six goals and providing three assists in 24 appearances across all competitions.
His performances earned him a place in Egypt coach Hossam Hassan's preliminary squad for the World Cup, although he was left out of the final squad that travelled to the United States.
Midfielder Ali Mahmoud scored four goals and registered four assists in 33 appearances for Enppi last season.
Last month, Ahly announced the appointment of Moroccan coach Houcine Amouta as their new manager.
Ahly are reshaping their squad after a disappointing season in which they failed to win a major trophy.
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