A Swiss politician of the Social Democratic Party of Switzerland, Sommaruga replaced outgoing Didier Burkhalter and will serve a one-year term until December 31, 2015.
Switzerland's fifth female president, Sommaruga received the backing of 181 parliamentarians out of 210 in a vote in December.
Switzerland’s parliament in December elected Sommaruga as the Swiss president for 2015, replacing the head of the foreign affairs department whose term expired in December 31, 2014.
The current head of the Swiss economics department, Johann Schneider-Ammann, will serve as vice president for the year.
The presidential post rotates through the seven-member Swiss cabinet.
Sommaruga, 54, has served in the Swiss cabinet as head of the Federal Department of Justice and Police since 2010.
She studied to become a concert pianist before entering politics in 1999.