The 2008 Manly Warringah Sea Eagles season was the 62nd in the club's history. Coached by Des Hasler and captained by Matt Orford, they competed in the National Rugby League's 2008 Telstra Premiership.
With the departure of hooker Michael Monaghan, many questioned whether the Manly Warringah Sea Eagles could be as competitive as in 2007 and losses in the first 2 rounds seemed to confirm this. Manly Warringah's first win came in round 3 at Brookvale with a 52–6 thrashing of the New Zealand Warriors and followed this up with a 20–2 shutout of South Sydney. In the round 5 grand final rematch against the Storm, Manly were soundly beaten 26–4 and doubt about their premiership credentials resurfaced. In Heritage Round (Rd 6) Manly Warringah had a season defining last gasp win over bitter rivals Parramatta, with Manly overcoming injuries before and during the game including one to winger Michael Bani who had to be stretchered off the ground after being knocked out.
Manly Warringah seemed to use this game as a springboard and entered a dangerous run of form, notching up numerous impressive wins over top teams such as a 30–12 win over the Brisbane Broncos at Suncorp Stadium, a 42–0 annihilation of the Sydney Roosters at Brookvale Oval and a 34–14 win over the Gold Coast Titans at Skilled Park in round 17. In round 18 Manly avenged their opening round loss to bitter rivals and eventual preliminary finalists Cronulla with a 34–6 hammering of them at Toyota Stadium. In round 19, Manly once again faced historical rivals Parramatta and in a repeat of round 6, Manly lost halfback Matt Orford and lock Luke Williamson before the game, and after only minutes five-eighth Jamie Lyon and prop Jason King were forced off the field with injury. Despite the setbacks and an early challenge from the Eels, Manly ran away with the game and finished 28–10 winners.
Some hiccups against the Roosters in round 20, the Storm in round 22 and the Rabbitohs in round 23 meant Manly finished the regular season tied first with Melbourne and Cronulla but 2nd on points differential and Manly missed out on claiming their first minor premiership since 1997. In the qualifying final Manly faced 7th placed St. George at Brookvale. This game was club legend Steve Menzies' last game at Brookvale and he opened the scoring with an unusual charge down try in which after kicking ahead to himself and falling over, the ball bounced up and hit him in the head before he finally grounded it. Manly Warringah were easy 38–6 winners and departing Dragons centre Mark Gasnier was seen on the sidelines crying. After getting the week off, Manly faced the history-making New Zealand Warriors whose late season charge got them into 8th place where they became the first 8th placed team to advance past qualifying finals with a dramatic and rare defeat of the Storm at Olympic Park. Despite an early challenge, Manly Warringah crushed the Warriors 32–6 and showcased their trademark wall of defence and attacking flair. With the win, Manly Warringah qualified for their 17th grand final, where in a rematch of the 2007 decider, they would play the Melbourne Storm who had bounced back from the Warriors' loss with wins over the Brisbane Broncos and Cronulla Sharks.
The story was very different for the Sea Eagles this time around as they decimated the Storm 40–0 to win their seventh premiership in front of 80,388 at ANZ Stadium. It was Michael Monaghan's replacement, the previously unknown Matt Ballin who scored the first try of the match. The game was also notable for winger Michael Robertson's hat-trick and retiring legend Steve Menzies' try 10 minutes from full-time, which he scored after coming back onto the field to replace the injured Steve Matai. Manly prop forward Brent Kite was awarded the Clive Churchill Medal after a powerhouse display which included a classy try in the 58th minute. This is the largest winning margin in a grand final in rugby league history.