After the festive nature of a parade on Saturday through the streets of Washington DC, the political demonstration could be the main event of the weeks-long WorldPride celebration, which moves around the globe every two years.
It occurs at the Lincoln Memorial at a time of high tension over LGBTQI rights in the US.
Speakers are certain to rail against Trump, who has issued executive orders limiting transgender rights, banned transgender people from serving in the armed forces and rescinded anti-discrimination policies for LGBTQI people.
The White House has defended its dismantling of diversity, equity and inclusion programs, calling the Diversity, Equity, and Inclusion (DEI) framework a form of discrimination, and said its transgender policy protects women by keeping transgender women out of shared spaces.
The Trump administration has also touted its appointment of a number of openly gay people to cabinet posts and judgeships as evidence that Trump aims to serve all Americans.
Before the main rally, transgender supporters will hold their march to protest Trump's rhetoric and myriad state laws around the country that ban transgender health care services for minors.
Backers of those laws say they are attempting to protect minors from starting on a path they may later regret.
The transgender rally will march from the offices of the Human Rights Campaign, the largest LGBTQI organisation in the US, toward the Lincoln Memorial, which is considered hallowed ground in the US civil rights movement as the site of the King speech and the March on Washington that preceded historic legislation such as the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
