Cate, who was the vice president of the San Diego County Taxpayers Association, defeated Carol Kim in the runoff election last month for District 6, which includes Mira Mesa, Kearny Mesa and part of Clairemont Mesa.
Cate is also a former council staff member for Kevin Faulconer, who is now the mayor.
“Mayor Faulconer, fellow council members, I look forward to working with you to improve San Diego's neighborhoods,'' Cate said.
“Yes, we're all going through trials and tribulations, but I see these as opportunities, not challenges,'' he said. ``Know that I am here, just as you are, to improve the quality of life for all residents in America's finest city.''
Cate's ascension into office allowed the council to choose a new leader. Such a vote had been scheduled for Monday, due to a quirk in the council rules, but it was postponed until Wednesday so Cate could have input.
Lightner, who represents La Jolla and Carmel Valley, replaced Todd Gloria as council president. Gloria, who filled the position for two years, was lauded by representatives of organized labor, the gay and lesbian community and environmental groups, but he failed to muster a majority of other council members.
He was nominated for a third year by Councilman David Alvarez, who gave an impassioned speech on his behalf, but his motion failed by a 5-4 margin.
Lightner was then nominated by Councilwoman Marti Emerald, who said she had “a great sense of promise that Sherri would be an excellent president.''
“She shares many of the same values that Todd has exhibited in the field and she's done the same thing -- she's stood for the same issues,'' Emerald said.
Lightner was an engineer for 23 years for General Atomics and Rohr Industries, after which she became a consultant and community activist.
She was first elected in 2008 and was reelected in 2012. She was the council president pro tem, or Gloria's second-in-command.
Her colleagues named her president on a 7-2 vote, with Alvarez and Gloria dissenting. That followed nearly 90 minutes of public comment in which everyone supported Gloria and praised him for moving the city past the scandals of former Mayor Bob Filner.
Councilman Scott Sherman said Gloria was the right guy at the right time, but on most boards, the job of president rotates routinely.
“There's limits on your time in the presidency -- there just is,'' Sherman said.
Lightner said she has worked hard to be a "fair, open-minded and independent'' councilwoman.
"We need to continue to be advocates to strengthen the voices of each of San Diego's diverse neighborhoods,'' she said. ``We need to improve police salaries, update our city's charter, approve the Climate Action Plan, address our infrastructure and water needs, and put more city services online to make city government work better for our citizens.''
She said she was "honored that my colleagues trust and respect my leadership" and "am proud to stand up and serve the city of San Diego as the first female council president."
Mayor Kevin Faulconer issued a statement congratulating Lightner.
“We already have a great working relationship and I look forward to working together to create more opportunities for all San Diegans,'' Faulconer said. “I would also like to commend Councilmember Todd Gloria for his leadership over the past two years and for working collaboratively with me to get the city back on track.''
The council president wields considerable power over setting meeting agendas, determines committee assignments and often appears with the mayor in a ceremonial role.
At a ceremony at Golden Hall, Alvarez and Lorie Zapf were sworn-in for second terms. Alvarez represents Barrio Logan and South San Diego communities.
Zapf, who had represented Cate's District 6, shifted over to District 2 -- Point Loma, Mission Bay, Bay Park -- for reelection because of a change in City Council boundaries.
Myrtle Cole began her first full term on the panel, representing Southeast San Diego. She took office last year after a special election that followed the resignation of Tony Young.
Ed Harris, who served on the panel for eight months after Faulconer became mayor, stepped down to make way for Zapf. He said he will resume his duties as a lifeguard next month.
Around 25 demonstrators stood quietly along a side wall of the cavernous hall for the inauguration ceremony, quietly holding their hands in the now-familiar “hands up, don't shoot'' symbol from the protests in Ferguson, Missouri, where a police officer shot an unarmed black man.
They also placed their hands at their throats to signify the death of a man in New York, who asphyxiated during a struggle with an officer.
They didn't disrupt the ceremony, however, and waited for the event to end before marching through the room and chanting.