The Izod Center in East Rutherford, New Jersey was originally supposed to host SummerSlam, but due to its closure in April 2015, the event was relocated.

Dubbed "The Biggest Party of the Summer",[3] it is one of the promotion's original four pay-per-views (PPV), along with WrestleMania, Royal Rumble, and Survivor Series, referred to as the "Big Four".

[5][6] Announced on October 13, 2014, the 2015 event was the 28th SummerSlam and was scheduled to be held on August 23, 2015, at the Barclays Center in Brooklyn, New York.

[15] Four months later, Lesnar defeated John Cena at SummerSlam to win the WWE World Heavyweight Championship,[16] but lost it the following year at WrestleMania 31 in his match against Roman Reigns when Seth Rollins cashed in his Money in the Bank contract and won the championship.

[26] On the July 13 episode of Raw, Charlotte, Becky Lynch, and NXT Women's Champion Sasha Banks made their WWE debuts; Charlotte and Lynch allied with Paige, later naming their team "PCB", while Banks allied with Naomi and Tamina, naming their group "Team B.A.D.".

[28] At Battleground, The Prime Time Players (Darren Young and Titus O'Neil defeated The New Day (Big E and Kofi Kingston) (with Xavier Woods) to retain the WWE Tag Team Championship.

[18] On the July 20 episode of Raw, Los Matadores (Diego and Fernando) defeated the Prime Time Players, after a distraction by the New Day.

[19] On the July 27 episode of Raw, The Lucha Dragons (Kalisto and Sin Cara) defeated Los Matadores.

[29] On the July 30 episode of SmackDown, The Lucha Dragons and Los Matadores defeated The New Day and The Ascension (Konnor and Viktor).

[30] On the August 3 episode of Raw, The New Day and The Ascension defeated The Lucha Dragons and Los Matadores in a rematch.

[31] On the August 6 episode of SmackDown, The Prime Time Players teamed up with Mark Henry to defeat The New Day.

[32] The Prime Time Players were then scheduled to defend the championship against The New Day, Los Matadores, and The Lucha Dragons in a fatal four-way tag team match at SummerSlam.

[27] On the August 10 episode of Raw, where Amell was again a special guest, Neville defeated King Barrett, but was then attacked by Stardust.

[26] On the June 29 episode of Raw, Cesaro defeated United States Champion John Cena by disqualification after being attacked by Owens, therefore not winning the championship.

On the July 20 episode of Raw, Cesaro teamed up with Cena and Randy Orton to defeat Owens, Rusev and Sheamus.

[18] On the July 20 episode of Raw, Orton, John Cena and Cesaro defeated Sheamus, Kevin Owens and Rusev.

[29] On the August 3 episode of Raw, Orton, Dean Ambrose and Roman Reigns defeated Sheamus, Bray Wyatt and Luke Harper.

[31] On the August 10 episode of Raw, Orton defeated WWE World Heavyweight Champion Seth Rollins by disqualification after being attacked by Sheamus, therefore not winning the championship.

[37] On the May 18 episode of Raw, Lana ended her association with Rusev and started a relationship with Dolph Ziggler, turning face in the process (storyline).

[38] After making numerous unsuccessful attempts to sway Lana from Ziggler, Rusev started a relationship with Summer Rae (storyline).

[42] Next, The Prime Time Players (Darren Young and Titus O'Neil) defended the WWE Tag Team Championship against The New Day (Big E and Kofi Kingston), The Lucha Dragons (Kalisto and Sin Cara), and Los Matadores (Diego and Fernando) in a fatal four-way tag team match.

Also, he criticized the idea of the Undertaker as the first man who defeated Lesnar in a singles match since WrestleMania 29, saying that "The Streak, [...] was sacrificed for a retirement tour".

[43] Jason Powell of Pro Wrestling Dot Net praised the Cena vs. Rollins and the Undertaker vs. Lesnar, but likewise criticized both finishes.

[44] Benjamin Tucker of Pro Wrestling Torch attended in person both WWE SummerSlam and NXT TakeOver: Brooklyn (a day earlier in the same venue).

Tucker criticized SummerSlam in comparison to TakeOver, saying that "the main show writing could learn something from NXT, not WCW 2000", because "NXT provided simple stories, but they were easy to follow and made the viewer root for the good guys to prevail", in addition to "no chicanery".

[49] After Roman Reigns and Dean Ambrose's victory over The Wyatt Family, a rematch was booked the following night on Raw.

Midway through the match, a mysterious man (later revealed to be Braun Strowman) interfered on behalf of The Wyatt Family.

[50] On the following night's Raw, The New Day (Big E and Kofi Kingston, with Xavier Woods) defeated The Lucha Dragons (Sin Cara and Kalisto).

[52] Kevin Owens started setting his sights on the WWE Intercontinental Championship, leading to a feud with champion Ryback.

[54] On the September 14 episode of Raw, Ryback was granted permission by The Authority to defend the Intercontinental Championship against Owens at Night of Champions.