The nuptials were kept secret until earlier this week when Commerce Secretary Wilbur Ross introduced Mnuchin at a conference in Washington.
While announcing Mnuchin at a conference in Washington, Ross said he and his wife "extend our congratulations and look forward to seeing you Wednesday your dear fiancée, Louise Linton, on Saturday", according to a Washington Post report.
Aside from the Trumps and Pences, guests included White House Press Secretary Sean Spicer and his wife Rebecca Miller, Housing and Urban Development Secretary Ben Carson and Secretary of Veteran Affairs David Shulkin.
The wedding is taking place at the Mellon Auditorium, a historic government-owned public space that is connected to the US Environmental Protection Agency's headquarters and right around the block from the Trump International Hotel.
First Lady Melania Trump arrived alongside the President in a pink Gilles Mendel gown of silk and chiffon.
However, the bride was the cynosure in a white lace top and skirt, and a diamond tiara, while the groom wore black tails and a white bow tie.
About 300 guests reportedly attended the wedding.
Mnuchin, 54, and Linton, 36, have been engaged since 2015. Mnuchin, who had previously worked at Goldman Sachs and a film production company, apologized in March after it seemed he had promoted The LEGO Batman Movie, on which he was an executive producer. Mnuchin and Linton are to be married Saturday, June 24, 2017.