"It's a deal I'm proud of and one I'm looking forward to bringing you tomorrow," Jerry Jordan, president of the Philadelphia Federation of Teachers, wrote in a message to members.
Details on the agreement are expected to be released on Wednesday.
Jordan said roughly 13,000 teachers and other staff were negotiating Tuesday night before the current contract expired at midnight.
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Luigi Borda who works at the Masterman School spoke with Action News earlier in the evening before the agreement was reached.
"We're still talking about a fair contract on the day that school started, our energies have to go with that. So it's hard to feel valued when that's going on," Borda said.
Borda has been an educator for more than three decades. He says along with a liveable wage, safe working conditions are a big concern. Teachers have expressed concerns about asbestos at the school.
He says that is on top of the concerns of coronavirus.
"It also speaks to the fact that teachers are given more to do, we are now tasked trying to manage that, which has been a Herculean task," Borda said.
Last October, the union agreed to a one-year contract extension, that included a 2% pay increase for teachers.
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"Fair wages, benefits, those are working conditions that I 100% support, but it's definitely a double-edge sword. As a parent, I'm going to have to figure out what to do with my childcare, but I also support the teacher's right to strike if they need to," said Councilmember Kendra Brooks.
President Jordan will present the tentative agreement and take an informal "voice vote" Wednesday at 6 p.m.