They had a son named Bryce Thadeus age 13.
Ulrich dated Danish actress Connie Nielsen from mid 2004 until 2012, after his divorce from Skylar and the couple had their first child, Bryce Thadeus Ulrich-Nielsen, (b. 2007) in San Francisco.
From a Danish article from the magazine Cover:
Connie Nielsen: ''He is an active person, a doer and the kind of person that invites you to dance in a lovely way. I fell in love with his amazing appetite for life. I admire that,” she says with a kind look in her eyes. “I don’t think he’s good for you if you’re a passive person. Then he would simply be too big a mouthful. Another thing I respect is his honesty. He’s says things without beating about the bush,” Connie says about the man she met in Hotel d’Angleterre in 2004. They were both visiting Denmark because of something work-related. Lars had to play a concert in Parken. She had to promote her first Danish film, Brødre (Brothers). Since then their relationship became known in Denmark and they were both chased by journalist wether they were going to visit family in Jylland (Jutland) or take a trip to Copenhagen. “But we actually met a lot earlier. It was Sean Penn who introduced us for each other over a couple of drinks in New York. My first impression was that he was relaxed, reliable, unsnobbish and well balanced,” she kindly continues. “Now it’s about getting as much time with each other as possible. And make it work with his two sons and my Sebastian, but its going fine, and it helps a lot that Lars is as organized as he is. I can use a little of that in my life.”