Pepe Julian Onziema (born November 30, 1980) is a Ugandan LGBT rights and human rights activist. He began his human rights work in 2003.

Onziema is the Director of Programs at Sexual Minorities Uganda (SMUG), an LGBTI advocacy organization. SMUG provides research, documentation, and evidence to advocate for policy change in Uganda. They also provide LGBT+ members with safety and protection from discriminatory hate crimes.

In 2012, he was named a Global Citizen by the Clinton Global Initiative for his work in human rights advocacy.

In 2014, Onziema formed a coalition of 55 Ugandan civil society organizations to protect LGBT rights in the country. That year, UK-based charity Stonewall named Onziema Hero of the Year.

A trans man, he has participated in organizing LGBT pride celebrations in Uganda.

As of 2019, Onziema has been arrested or detained seven times, incurring violence in which he lost hearing in his left ear and needed to be hospitalized.

Onziema was assigned female at birth. He first questioned his gender by the age of 6, and began questioning more at the age of 9. By puberty, he expressed himself in ways that "affirmed [him] as a male person." Although he could have transitioned anywhere, he chose to stay in Uganda and transition there to affect the country's culture.

He came out in the 1990s, and his mother was supportive throughout his life, including his advocacy work.

As of 2020, he has found acceptance throughout his community, attending village elder meetings being embraced as "the son [he] truly [is]."

On December 18, 2012, he was invited on the Ugandan television show Morning Breeze hosted by Simon Kaggwa Njala, to join a debate about sexual minorities and their situation in Uganda.

The interview later turned into an animated dispute when pastor and anti-gay activist Martin Ssempa came into the show trying to discredit Onziema, with fruits and vegetables, while shouting in both English and Luganda over Njala. The interview itself was uploaded to the internet and became the subject of various internet memes, commonly titled "Why Are You Gay?", based on the first question Njala asked Onziema.

In 2014, Onziema denounced a local tabloid list of "200 Top Homo" Ugandans, many of whom did not identify as gay. The tabloid was released just one day after the president enacted the Anti-Homosexuality Act, 2014 that included life imprisonment. Onziema criticized the article for directly inciting hate crimes, such as violence and murder, against members of the LGBT community. One of these occurred to David Kato, his coworker in Sexual Minorities Uganda, who had been murdered following his publication in an article titled "Hang Them."

That year, Onziema "led a successful challenge of Uganda's infamous law that made homosexuality a crime punishable by death." He united 55 Ugandan civil society organizations including parents, educators, and caregivers to "form a coalition to fight the law." CBC Radio reported, "Six months after the bill was passed, Onziema's coalition scored a court victory, striking the law down on a technicality."

In 2013, Pepe was shortlisted for the David Kato Vision and Voice Award, an award in honour of his murdered friend and colleague, and fellow advocacy officer for Sexual Minorities Uganda, David Kato.

In 2014, he was interviewed by John Oliver on the American television series Last Week Tonight about the human rights situation for LGBT people in Uganda. Initially, Onziema was "very skeptical" and did not want to be on the show, as Onziema felt "done with media." However, Oliver made Onziema feel very comfortable and respected, particularly Oliver introducing Onziema as a trans man. The episode positively affected Onziema's reputation in Uganda, causing him to receive more support than before from locals.

In 2016, Onziema was one of multiple activists arrested at Uganda's 5th gay pride event in Kampala, Uganda. The police put Onziema in police custody and ordered other inmates to beat him up so severely that he had to be hospitalized, losing hearing in his left ear. Ugandan police claim no one was injured, while Onziema claims they are not listening to members of the community who remained as survivors or victims. He claims the police not only administer physical violence to members of the queer community, but also psychological trauma.

In Uganda Pride 2022, when asked how the week's events fit into the global struggle for LGBT equality, Onziema replied:

Uganda has been named as one of the worst places to be gay, which means that all eyes are on Uganda. For us to celebrate our visibility [amidst all the hostility] is very important.

Despite the hardships he faced in Ugandan prisons, Onziema has stated,

I love this country to bits, and my work is to make it the kind of place that it really is. It's beautiful. It has beautiful people, and I'm just doing my ounce of something to preserve it for people who will come after me.

• LGBT rights in Uganda
• Stella Nyanzi