The happy couple was surrounded by family and friends, including big sister Jessica Simpson as a matron of honor and the bride's 5-year-old son, Bronx Wentz. Simpson wore Neil Lane jewelry that complemented her engagement ring designed by the jeweler.
Simpson, 29, and Ross, 26, announced their engagement on Jan. 13 via Twitter.
"The love of my life said YES!!!!!!" Ross wrote, with Simpson adding, "My baby love and I are ENGAGED!!! Hallelujah Hawaii!!!"
The announcement was soon followed by several celebrations, including an engagement party in March at the home of Simpson's mother, Tina, and a bohemian bridal shower earlier this month at Jessica's L.A. home.
Simpson, who was previously married to rocker Pete Wentz, was first spotted holding hands with the Hunger Games: Mockingjay star in July last year, walking out of the Sunset Marquis Hotel in Los Angeles.
The couple were recently spotted celebrating Ross's birthday on Aug. 26 at STK Downtown in New York, where a source says, "They were excited and talking about the upcoming wedding. Evan and Ashlee were kissing each other nonstop all night."