The 45-year-old has little experience in politics but attracted voters who are appalled by corruption and mainstream politics. Her election to the largely ceremonial post defied a wave of gains for far right populists across Europe.
"I'm not here to rule, I'm here to serve,"Caputova said in her inauguration speech. A lawyer by profession, Caputova became known for leading a successful fight against a toxic waste dump in her hometown of Pezinok, for which she received the prestigious Goldman Environmental Prize in 2016.
A divorced mother of two, she is in favor of gay rights and opposes a ban on abortion in this conservative Roman Catholic country. She only recently became vice chairman of Progressive Slovakia, a new pro-EU party that won the recent European Parliament election in Slovakia
Caputova resigned from her party post after winning the first round of the presidential vote. Like her popular predecessor Andrej Kiska, who didn't run for a second term, she is firmly supporting Slovakia's membership in the European Union and NATO.
She said the EU and NATO give her country "happiness and privilege that (previous) generations could only dream of." Kiska backed Caputova in the presidential vote in March when she beat European Commission Vice President Maros Sefcovic in a runoff vote.
Kiska's five-year term in office was marked by clashes with populist former prime minister Robert Fico and his leftist party, a dominant political force that was tarnished by corruption scandals. Caputova and Kiska had both supported the massive anti-government street protests last year following the slayings of an investigative reporter and his fiancee that that led to the fall of Fico's coalition government. Investigators have linked Jan Kuciak's death to his work probing possible widespread government corruption.
The president of the nation of 5.4 million people has the power to pick the prime minister, appoint Constitutional Court judges and veto laws. Parliament can override the veto with a simple majority, however. The government, led by the prime minister, possesses most executive powers.
Caputova hosted a lunch for the elderly later Saturday. "I want to be the voice of those who are not heard," she said.