The role of speaker makes Kamerhe, a close ally of President Felix Tshisekedi, the Central African country's number two authority.
Of the 407 members of parliament who cast ballots on Monday, 371 voted in favor of Kamerhe's candidacy for speaker. MPs were also set to vote on candidacies for six other positions in the lower house.
The vote clears the way for Congo to name a government, which it has not had since the December 2023 presidential election that handed Tshisekedi a second term.
Tshisekedi named Judith Suminwa as Congo's first female prime minister on April 1.
The vote had been scheduled for May 18 but was delayed by Tshisekedi.
On May 19, Congolese security forces said they had foiled an attempted coup and repelled an attack on Kamerhe's home in the center of the capital Kinshasa. Kamerhe's spokesman, Michel Moto Muhima, said two guards were killed in the attack.
The Sacred Union, Tshisekedi's coalition, has a majority in parliament with at least 90% of elected members of the 500 seats in parliament.
Kamerhe, 65, campaigned with Tshisekedi in the 2018 presidential election.
Kamerhe has previously served as Tshisekedi's chief of staff and as deputy prime minister of the economy. In 2020, he was arrested in a graft probe.