Watford winger Sarr arrived in Cameroon injured and made his first appearance in the quarter-final against Equatorial Guinea, coming off the bench to score in a 3-1 victory.
Sarr also came on as a substitute in the semi-final win over Burkina Faso, convincing coach Aliou Cisse to select him ahead of Bamba Dieng on the right-wing in the only change to their line-up.
Mane was selected to play on the other side of the attack for a Senegal side looking to win the Cup of Nations for the first time.
Egypt has won the title a record seven times, although skipper Salah is looking for his first AFCON crown having made his Pharaohs debut in 2011, a year after they were last African champions.
Emam Ashour of Zamalek replaced the suspended right-back Omar Kamal in the only change to the Egypt team that started their semi-final against Cameroon, which they won on penalties.
Coach Carlos Queiroz was suspended after being shown a red card on the touchline in that game.
Starting line-ups:
Senegal (4-3-3)
Edouard Mendy; Bouna Sarr, Kalidou Koulibaly (capt), Abdou Diallo, Saliou Ciss; Idrissa Gana Gueye, Nampalys Mendy, Cheikhou Kouyate; Ismaila Sarr, Famara Diedhiou, Sadio Mane
Coach: Aliou Cisse (SEN)
Egypt (4-3-3)
Mohamed Abou Gabal; Emam Ashour, Mohamed Abdelmonem, Mahmoud Hamdy El Wensh, Ahmed Fatouh; Mohamed Elneny, Hamdy Fathy, Amr El Solia; Mohamed Salah (capt), Mostafa Mohamed, Omar Marmoush
Coach: Carlos Queiroz (POR)
Referee: Victor Gomes (RSA)