Stars-a-plenty — both Lollapalooza bands and singers — plus celebs in town for the mega-music festival — made the scene all over Chicago this weekend. Big Boi of Outkast fame was a huge attraction to Parliament’s Lolla after-party, that attracted Jesse Spencer, Monica Raymund and a slew of “Chicago PD” and “Chicago Fire” cast and crew, plus Sophia Bush — who also attended Gilt City Chicago’s “Better Than Backstage Rooftop Pool Party” at the EnV Chicago roof lounge. … Leading up to Soho House Chicago’s Aug. 11 launch, the celebrity club drew Lolla founder Perry Farrell, Calvin Harris, Connie Britton, Sophia Bush, Foster the People, London Grammar and Jon Batiste to its late night bash Saturday. … While in town for Lolla, Danny Masterson checked out RPM Italian and Bistro Paris Club Bistro & Bar, plus Studio Paris, as did pop group Fly Panda and Lady Gaga’s producer Paul Blair (DJ White Shadow).Ed Westwick and Mark Salling were also seen at RPM Italian. Ditto for Parquet Court, after their Lolla performance. … Chicago native and actor Michael Pena was spotted at a pop-up listening party for Sal Masekela’s new album at lower-level club Sub 51. … Joe Jonas and (separately) Claire Holt — plus Jennie Garth were seen at Beatrix, with all three of them (again separately) also spied at Hub 51. … Jonas, by the by, surprised the crowd by spinning a set at the Rolling Stone party at Studio Paris. He also checked out Celeste’s new third floor lounge. … Other Hub 51 sightings included Jessica McNamee, Shelby Phillips, AFI, Smallpools, GTA, Josh Henderson, Kellan Lutz, Ryan Beatty, RatKing, Fitz and the Tantrums and Of Varona. … Bub City drew in Alanna Masterson as well as Crass Mammoth and Roadkill Ghost Choir.Arctic Monkeys drank zombies and scorpion bowls at the Three Dots and a Dash tiki bar. … Krewella was seen munching on Chicago’s famed Garrett’s Popcorn at Nellcote, where so many bands dined over the weekend — including Blood Orange, Cash Cash, Bombay Bicycle Club, Jawar Ma and Lucius.

Whew! Whatta Weekend!!!