EDIT: This is information from 2011, for current info... click here!) There are many churches offering services in several languages during the Christmas weekend. The main denominations are Church of Sweden (Lutheran) and Catholicism. Here are the mass times that can be of interest:
Storkyrkan (Lutheran)- located in Gamla Stan.
-December 24th: Christmas prayer at 5pm and midnight mass at 11pm. Both in Swedish. They will be playing Christmas music at 4:30pm.
-December 25th: High Mass at 11am in Swedish.
-December 26th: High Mass at 11am in Swedish.
St Jacob's Church (Lutheran)- located next to Kungsträdgården.
-December 24th: Christmas prayer in Estonian at 2pm and Worship in English at 6pm.
Katolska Domkyrkan (Catholic)- located on Södermalm.
-December 24th: Christmas service in Italian at 9pm and in Croatian at 10pm. Midnight Mass (Swedish/Latin ?).
-December 25th: Mass in Italian at 8:45am, High Mass at 11am, in Spanish at 2pm, in Polish at 5pm and in Swedish at 6:30pm.
-December 25th: Mass in Swedish at 09:45am and in Croatian at 11am.
St Eugenia (Catholic)- located next to Kungsträdgården.
-December 24th: Christmas prayer in Swedish at 8pm, mass in Swedish at 10pm and midnight mass (12am)in English.
-December 25th: High Mass in Swedish at 11am and Christmas Mass in English at 6pm.