Lam, 59, was widely seen as Beijing's preferred candidate when she was elected in March by a mainly pro-China committee representing special interest groups, from real estate and agriculture to teaching and medicine, as well as lawmakers.
But critics have said she will only further polarise a society riven by mass protests three years ago against Beijing's interference in the affairs of the semi-autonomous city and still divided between those loyal to China and those concerned about its growing influence.
Before landing the top job, Lam served as deputy to her highly unpopular predecessor Leung Chun-ying, slammed as a puppet of Beijing.
Appointed by Leung as chief secretary in 2012, the new leader promoted a Beijing-backed political reform package rejected as "fake democracy" by opponents.
Bespectacled Lam -- whose Cantonese name is Lam Cheng Yuet-ngor -- is nicknamed "lai-ma" or "wet-nurse" by opponents in a jibe over what they say was fawning loyalty towards her former boss.
A mother of two adult sons, Lam is known as a tough and effective enforcer.
In 2007, she personally faced off with protesters over the demolition of a historic pier built during Hong Kong's colonial days under British rule. The landmark was ultimately destroyed.
At the height of the mass street protests in 2014 -- known as the "Umbrella Movement" -- she met with student representatives in a televised meeting about the political reform dispute.
Ultimately activists failed to win concessions on democratic reform, including fully free leadership elections.
Lam was an activist herself during university in the 1970s, with one photo published in the South China Morning Post showing her marching in protest against the expulsion of four "leftist" students.
She came from humble origins, growing up in a modest family of five children in the crowded district of Wanchai.
But recent gaffes have fanned criticism that Lam -- who is usually elegantly dressed and sports a short coiffed hairstyle -- is out of touch with ordinary people.
She appeared unfamiliar with how to use the city's ubiquitous "Octopus" travel card to get into the subway platform.
She was also mocked for a lack of common sense after an anecdote related to reporters -- about a late-night hunt for toilet paper -- revealed she didn't know where to buy essentials in a city packed with convenience stores.
In an interview last month with Chinese state news agency Xinhua, Lam said the government must imbue the young generation with a sense of Chinese national identity.
The government will "strictly enforce the law" against any acts advocating Hong Kong independence, she told Xinhua.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)