LGBTQ people are fully protected from discrimination in the areas of employment, housing and public accommodations; the state enacting comprehensive anti-discrimination legislation regarding sexual orientation and gender identity in 2006.

A 2019 survey from the Public Religion Research Institute showed that 74% of residents supported anti-discrimination laws protecting LGBTQ people.

Several Native American tribes in modern-day Washington recognize individuals who act, behave and live as the opposite gender, now referred to as "two-spirit".

The Washington Supreme Court struck down the law as unconstitutional in 1942, holding that the "mental condition [of the accused] did not allow them fully to understand the nature of the notice".

The defendant, Keith Rhinehart, challenged the law as a violation of his right to privacy and on the grounds of vagueness and the establishment of religion, though the Court held that these contentions had "no merit".

[5] In 1972, a same-sex couple holding hands at a Seattle skating rink were arrested, resulting in protests and renewed debate surrounding the sodomy law.

[6][7] In March 2024, Governor Jay Inslee signed a bill that would add LGBT history to the state school curriculum, as part of other updates and changes intended to make it more representative and inclusive of minorities.

The first declaration of its kind in Washington, it includes commitments (on top of protections already present in state law) to the "equal and dignified treatment" of LGBTQ residents at the municipal level.

In the 2006 consolidated appeal of Andersen v. King County, the Washington Supreme Court narrowly upheld the constitutionality of that law barring same-sex marriages.

[17][18] Governor Chris Gregoire signed a law authorizing same-sex marriages on February 13, 2012, but opponents gathered enough signatures to force a voter referendum on the legislation.

Washington state law permits a legally competent adult to petition to adopt without respect to marital status.

[36] The protections were added in 2006 with Washington House Bill 2661, signed into law by Governor Christine Gregoire, a member of the Democratic Party.

Discrimination based on sexual orientation in state employment had already been prohibited since 1991 by an executive order of Governor Booth Gardner.

Moreover, the state's anti-bullying law prohibits bullying on the basis of sex, race, creed, religion, color, national origin, sexual orientation, gender expression, gender identity, honorably discharged veteran or military status, presence of any sensory, mental or physical disability, or use of a trained dog guide or service animal.

[44] The Arlene's Flowers lawsuit was a group of merged civil suits brought against Arlene's Flowers of Richland, Washington, US, by a couple whose longtime florist declined service of their same-sex wedding, represented by the American Civil Liberties Union (ACLU), and by Washington Attorney General Bob Ferguson.

[48] On November 15, 2016, state Attorney General Ferguson personally argued the case before the Washington Supreme Court; the hearing was held before an audience at an auditorium on the campus of Bellevue College.

[61] Stutzman opted to settle with Ingersoll in November 2021, paying him $5,000, as she was getting close to retirement and wanted to stop accumulating legal fees related to the case.

[62] Washington state law criminalizes "malicious harassment" and violence motivated by the victim's sexual orientation or gender identity and expression.

[63] In February 2020, the Washington State Legislature passed a bill, by a vote of 90–5 in the House and 46–3 in the Senate, to abolish the gay panic defense.

Surgery, puberty blockers, hormone replacement therapy and other transition-related healthcare for transgender people is covered under health insurance and state Medicaid policies.

[73][74][75] Seattle allows single occupant restrooms in city facilities and public places to be used by any person, regardless of sex or gender identity.

[76] Since January 1, 2022 under the "Gender Affirming Treatment Act" in Washington State will legally cover sex reassignment surgery for insurance purposes under Medicaid.

[81][82][83] In October 2023, prisons within Washington state (under court order and rulings) are legally required to provide gender-affirming healthcare and/or sexual reassignment surgery to inmates.

[86] On February 13, 2014, the Washington House of Representatives voted 94–4 in favor of a bill that would have prohibited health care providers from trying to change the sexual orientation of minors.

His challenge (represented by the Alliance Defending Freedom) was rejected in August 2021 by a federal district court judge in Tacoma, Washington.

[100][101] A 2022 Public Religion Research Institute poll found that 83% of Washington residents supported same-sex marriage, while 15% were opposed and 2% were unsure.