The model-turned-actress' engagement was announced in May, following her divorce from actor Giovanni Ribisi last year.
And on Sunday the blonde beauty walked down the aisle in Brooklyn, New York, breaking tradition by wearing a pink wedding dress by Molly Goddard. Joel, meanwhile, looked dapper in a bright white suit with a blue tie.
The star shared her happy news on Instagram by posting a photo of herself and Joel sat at what appeared to be a table in the reception, captioning the cute shot of them kissing: “I get to marry my best friend today.”
Designer Henry Holland also posted photos on his page - one of Agyness, 33, posing with a bouquet while another showed the bride and groom standing together outside the church.
The happy couple have flaunted their relationship on social media since becoming official in May 2014. To celebrate their one year anniversary the pair went to watch the Golden State Warriors play basketball in Oakland, California, sharing a snap on Instagram.
Agyness became engaged to Friends star Giovanni in 2012 and said at the time of their marriage in 2013 that she just "knew" he was the one for her.
However, they filed for divorce in early 2015, which was finalised last November.
Agyness made her move into acting in 2010's Clash of the Titans, and has two films - Patient Zero and The Titan - currently in post-production. However she still dabbles in modelling, and walked for Saint Laurent in its fall 2015 show.