“The party of [France's postwar leader] General (Charles) de Gaulle … our political family, will have a female candidate in the presidential election. I am thinking of all the women of France today. I will give everything to triumph,” she said after the result was announced.
Ms Pecresse, a former minister in the presidency of Nicolas Sarkozy, won almost 61 per cent of the vote among party members against right-winger Eric Ciotti, who obtained 39 per cent.
She has described herself as “one-third Thatcher, two-thirds Merkel".
“We are going to restore France's pride and protect the French,” Ms Pecresse said at the party's headquarters shortly after the results were announced.
But current opinion polls – that favour another victory for Mr Macron – showed her winning about 11 per cent of the votes at best in next April's election, giving her little chance of making it to a second-round run-off, let alone winning it.
She campaigned on promises to halve the number of residence permits for non-EU migrants, stiffen judicial sentences in tough neighbourhoods where police are under pressure, and ban women accompanying their children on school trips from wearing a Muslim headscarf.
“I feel the anger of people who feel impotent in the face of violence and the rise of Islamist separatism, who feel their values and lifestyle are threatened by uncontrolled immigration,” she said.
The former budget minister and government spokeswoman under Mr Sarkozy will struggle to differentiate herself from Mr Macron's pro-business, low-tax position.
She has said she would end the 35-hour working week, raise the retirement age to 65, cut 200,000 public sector jobs and build more nuclear reactors.
While the centre-right has ruled France for much of its postwar history, it has struggled in recent years, losing voters both to Mr Macron, who has occupied much of its territory, and to the far right.
Ms Pecresse can potentially appeal to the centre-right voters Mr Macron depends on, but will have to seek support from more conservative voters also courted by right-wing candidates.
The unexpected candidacy of far-right commentator Eric Zemmour has challenged the conventional wisdom that the presidential election will be a rerun of the 2017 duel between Mr Macron and the far-right National Rally's Marine Le Pen.
Taking aim at Ms Le Pen and Mr Zemmour, Ms Pecresse said: “You do not need to be an extremist to go on the offensive. You do not have to be insulting to convince.
“Unlike the extremists, we will turn the page on Macron but without tearing up the pages of French history.”