The Addicks finished in the top 10 last season, while Orient won promotion to the third tier as League Two champions.
Match preview
Charlton finished in 10th place last season, finishing with a total of 65 points from 42 games, and the steady haul of 38 points from 25 games under new manager Dean Holden has boosted playoff hopes this term.
The Addicks finished 16 points adrift of the top six, so Holden will be looking to fight closer to the promotion battle over the next 12 months, and improving home form could be crucial towards that - Charlton picked up 34 points from 23 matches at the Valley, recording nine wins, seven draws and seven losses, which was the 13th-best home record in the division.
Holden's side have only tasted defeat once in their pre-season preparations, suffering a 3-2 defeat to Scottish Premiership side Aberdeen after a clinical first-half display from the Dons.
Prior to that, the Addicks enjoyed victories over Welling United, Dartford, Gillingham, and Wealdstone, as well as sharing the spoils with Saturday's opponents and Championship outfit Millwall.
As for Leyton Orient, they enjoyed a successful 2022-23 campaign in League Two, winning the title and securing automatic promotion to the third tier in the process after an eight-year absence.
Although, the O's won the title with four games to spare, the primary concern manager Richie Wellens coming into this year will be the lack of goals scored by his side. Orient could only muster 61 goals in their title-winning campaign, the joint-fewest - along with Stevenage and Bradford City - in the top eight.
Indeed, the O's score more than twice on just four occasions last season, but questions in attack have been addressed somewhat, with the signings of strikers Dan Agyei and Joe Pigott.
Perhaps more alarmingly for Wellens, his side have only managed to win one of their pre-season friendlies, which was a 3-1 triumph over Brentwood on July 11, and have tasted defeat against the likes of Chelmsford City, Colchester United, Ebbsfleet United and most recently Bishop's Stortford.
Orient managed to pick up 40 points on their travels last season - level with Salford City and Mansfield Town - and Wellens will be eager to see his side start strongly here.
Charlton Athletic friendly form:
Leyton Orient friendly form:
Team News
Charlton striker Miles Leaburn has been ruled for the start of the season due to an ankle injury he suffered against Welling United.
Holden has a strong core at his disposal in the form of Michael Hector, George Dobson and Scott Fraser, and has also been able to add to that too, with the additions of Harry Isted, Panutche Camara and Alfie May.
As for the visitors, they have lost two of their top performers from last season in the form of Lawrence Vigouroux and Paul Smyth, to Burnley and Queens Park Rangers respectively.
However, Wellens has been able to add to his squad, bringing in Max Sanders, Ethan Galbraith, Darren Pratley and George Moncur.
Charlton Athletic possible starting lineup:
Maynard-Brewer; Hector, Jones, Ness; Asiimwe, Camara, Dobson, Fraser, Blackett-Taylor; May, Kirk
Leyton Orient possible starting lineup:
Howes; James, Beckles, Happe, Hunt; Brown, Galbraith; Archibald, Moncur, Agyei; Pigott
We say: Charlton Athletic 1-1 Leyton Orient
Considering both sides have lost key players and made a number of signings, we can see the teams cancelling each other out here, as it could take a few weeks for new arrivals to gel.