[citation needed] After three years as a civil servant in the Senate office of the Interior, Wowereit stood for election as municipal councillor in the Tempelhof district.

In 2003, Wowereit declared that "Berlin ist arm, aber sexy" ("Berlin is poor, but sexy"),[2][3] a description that reflected on the one hand the city's working class history and on-going financial woes, and on the other its cultural vibrancy, aided by a relatively low cost of living for a major European capital.

[4][3] The phrase helped to market the city to the rest of the world, and it drew in tourists, as well as attracting artists, writers, musicians and subsequently technology entrepreneurs.

[10] That same year, he appointed Turkish-origin politician Dilek Kolat Senator for Labour, Integration and Women.

[12] In the negotiations to form a Grand Coalition of Chancellor Angela Merkel's Christian Democrats (CDU together with the Bavarian CSU) and the SPD following the 2013 federal elections, Wowereit led the SPD delegation in the working group on cultural and media affairs; his counterpart of the CDU was Michael Kretschmer.

When Platzeck gave up his political offices for health reasons in July 2013, Wowereit was eventually appointed chairman again, despite much criticism.

[18] Wowereit announced his intention to resign at the end of 2014 due to the airport delays saying it was the "biggest failure" of his term in office, but that there were also other "several difficult times here.

"[19] Alongside Jutta Allmendinger, Wowereit co-chaired an independent expert commission on gender-based discrimination at Germany's Federal Anti-Discrimination Agency from 2015 until 2016.

[20] In 2017, he briefly arbitrated wage negotiations between Eurowings and UFO, a flight attendant trade union.

In coming out, prior to the 2001 mayoral elections, he coined the now famous German phrase "Ich bin schwul, und das ist auch gut so."

In his autobiography, Wowereit states that his decision to come out in public was made because after his nomination as candidate to become the Mayor of Berlin, he felt that the German tabloids were already "on the right track".

With his coming out, Wowereit wanted to beat the tabloids to it and prevent them from writing wild, sensational and fabricated stories about his private life.

In September 2007, Wowereit published an autobiographical book titled "…und das ist auch gut so.