Ulreich has largely played as an understudy to Manuel Neuer during his six seasons at the Allianz Arena, making 86 appearances in that time compared to 285 for Germany's number one goalkeeper in the same time frame.
Ulreich has made eight appearances this term, with Neuer having battled fitness problems in the course of the campaign.
Ulreich has won six Bundesliga titles, one Champions League and three DFB-Pokals for Bayern during his time as Neuer's number two.
The 34-year-old's previous contract would have expired at the end of this campaign.
"I'm very happy to stay on at FC Bayern," Ulreich said. "The cooperation with the whole team and especially with Manuel Neuer has grown into something special over many years.
"We're perfectly attuned to each other and I really enjoy my job. FC Bayern knows that I'm always there when they need me.
"The goal is to win more titles, that's what we're all here for, that's what we give everything for every day."
Bayern sporting director Hasan Salihamidzic added: "This contract extension shows the sporting value Sven has for our team.
"He was and always is a reliable performer when needed, but also in the changing room.
"It's hugely important for us that he's been very well attuned with Manuel Neuer in the training group of our goalkeepers for years.
"They both support each other, and we need that in this important position. I'm happy we'll continue working together."
