The 49-year-old, who previously served as the Minister of Foreign Affairs, took office on 8 July after being elected in May.
“During my presidency, I will stand up for the creation of a modern and strong Latvia, for a legal and just Latvia, for the wellbeing of the people, for an inclusive and respectful society,” he said during his inaugural speech.
“It is possible for all of us to achieve this by working together.”
The EU has had openly gay heads of governments, but Rinkevics makes history as the first to become a head of state.
He came out publicly in 2014 and has been a vocal champion of LGBTQ+ rights and equality ever since.
Despite being a somewhat ceremonial position, Latvia’s president has the power to veto legislation and call referendums.
Same-sex marriage is illegal in the country, though civil unions are allowed.
READ MORE: Ranking reveals the best and worst places to be LGBTQ+ in Europe
They do not, however, give the same benefits that heterosexual couples are offered, such as adoption rights.
ILGA-Europe’s annual ‘Rainbow Europe’ index ranked Latvia 37th out of 49 European countries based on where the best place to be LGBTQ+ is.
Part of the report said: “In November, the social opinion polling agency SKDS and Mozaika’s poll found that 49% had a neutral stance towards ‘homosexual’ people, 25% were accepting, and 23% condemned ‘homosexuality’. A third of the respondents said they did not know an LGBT person.”