Tasmania's transgender community is celebrating after landmark reforms to make gender optional on birth certificates passed their last parliamentary hurdle.

Tasmania's Lower House passed the Marriage Amendments Bill on Wednesday, after Liberal speaker Sue Hickey voted with the Opposition parties to allow debate.

The legislation had already been ticked off by the Legislative Council, but the government had sought to delay bringing on the bill in the Lower House for its final debate. The Government has opposed the amendments since last year, saying the Bill was hijacked by Labor and the Greens, was sloppily drafted, and could have unintended consequences. The legislation makes gender on birth certificates optional, and removes the requirement for transgender people to have surgery in order to have their gender recognised.