UPDATED: February 23, 2012, at 4:28 a.m.

Cambridge City Councillor Henrietta J. Davis was elected and sworn in as mayor of Cambridge just a few minutes after 8 p.m. at Wednesday's Cambridge City Council meeting.

The decision comes after weeks of failed attempts to select a new mayor. During the Council’s 10th ballot since the process began in January—the second ballot cast on Wednesday night—Davis garnered the necessary five out of nine councillors’ votes to earn herself the mayoral office.

“I’m very proud to be elected mayor of Cambridge,” said Davis after the meeting. “We have a lot of great things we’re going to do here, and I look forward to working with my colleagues to do them.”

Eight of the nine councillors sought the position, which is primarily ceremonial but comes with a significant pay increase and a spot on the Cambridge School Committee. Minka Y. vanBeuzekom, who was elected to the Council this past November, was the only councillor who never voted for him or herself.

On the first ballot of the night, Councillor E. Denise Simmons threw her support to Davis in what proved to be the turning point of the election.

“She has served with dignity and has done an extraordinary job on the school committee, so she asked me for my support, and I considered it, and there we are,” Simmons said.

Simmons had previously voted for Councillor Leland Cheung on every ballot since Jan. 9.

In the next round of voting, Councillors David P. Maher, Timothy J. Toomey Jr., and vanBeuzekom also realigned themselves behind Davis, giving her the five votes necessary to be elected mayor. After it was clear that Davis had won the election, Councillors Majorie C. Decker, Kenneth E. Reeves ’71, Craig A. Kelley, and Cheung switched their votes to Davis, giving her a unanimous victory.

VanBeuzekom was last in the Council’s alphabetical roll-call vote.

“I knew that it was momentous,” she said. “I was keeping track, and I had this big sheet­—she had four [votes], and I was going to be the fifth.”

Simmons, a former mayor of Cambridge, was elected and sworn in as vice mayor. Both terms last two years.

Wednesday’s council meeting was convened to discuss the ongoing budgetary issues of the Massachusetts Bay Transportation Authority, which will be cutting back on service and increasing fares. Members of the Cambridge delegation in state government were present, including Representative Martha M. Walz.

Walz expressed disappointment with the way Massachusetts Governor Deval L. Patrick ’78 has chosen to split up the budget.

“That is a judgement call with which I profoundly disagree,” said Walz, commenting on the funding allocated to the MBTA in Patrick’s proposed budget. “What the administration is saying is that we’re presenting two options and you can carry on, and so what we’re saying is that we need to have a third option.”

—Staff writer Maya Jonas-Silver can be reached at mayajonas-silver@college.harvard.edu.