The main House author of an English-only measure predicted the Senate would pass it like the House did.
Senate Bill 163, if passed, would let voters decide whether to make English the official language of state government.
If Rep. Randy Terrill is correct, the question will be decided by voters in November. The proposed constitutional amendment would not require the governor's signature.
The House passed Senate Bill 163 by a vote of 70-28 on Wednesday.
Terrill, R-Moore, said the measure passed by a greater margin than he expected.
House members spent more time on procedural matters than on the bill itself. It passed without debate.
The bill also contains exemptions for the languages of Oklahoma's 39 federally recognized tribes and allows the use of both Braille and sign language in government services. The legislation also contains a number of other specific, narrowly tailored exceptions for things such as public health and safety, as well as trade, commerce and tourism.
George Tiger, former speaker of the Muscogee (Creek) Nation Council, was among about 30 people who watched House members discuss the measure.
"We do appreciate the fact that our languages are being taken into consideration,” Tiger said.