Oglesby gave birth to daughter Breeze Beretta Johnston last month.
Johnston, 22, also has a 3-year-old son, Tripp, with 22-year-old former "Dancing with the Stars" contender Palin, the daughter of 2008 Republican vice presidential hopeful Sarah Palin.
Johnston and Palin broke up in 2009, briefly reconciled in 2010, then permanently ended their relationship a short time later.
TMZ said Johnston and Oglesby were wed Sunday at a ceremony attended by more than 100 friends and family members, but Tripp was not among the guests.
No other details were immediately available.
Bristol Palin wrote a book about being a single teen mom after she and Johnston broke up. She also starred in a reality TV show with Tripp and she appeared on the family drama series "The Secret Life of the American Teenager."
Johnston posed for Playgirl magazine.