According to Wikipedia, ESA has never had a crewed spacecraft. While this is reasonable, it's striking that no ESA crewed spacecraft is in development right now. What's the rationale behind this decision?
From 1985 to 1992, ESA worked on a human space program, using the Hermes spaceplane (to be launched by the Ariane 5 then in development). This program was cancelled due to rising cost and the loss of a sense of urgency: having an independent crewed spaceflight program was seen as non-critical. Basically they had 3 expensive programs: Hermes, Ariane 5 and the Spacelab laboratory (for use on the Space Shuttle) and could afford only 2 of those.
The project was subject to numerous delays and funding issues. In 1992, Hermes was cancelled, in part due to unachievable cost and performance goals, as well as the formation of a partnership with the Russian Aviation and Space Agency (RKA), which reduced the demand for an independent crewed spaceplane.
After that, the ISS program was built on almost world-wide cooperation in human spaceflight. ESA's crewed program supports the ISS with astronauts, training facilities, ISS modules and (a few years ago) a series of cargo flights using the ATV.
ESA's long-term plans are visible in e.g. the Future Launchers Preparatory Programme, and that does not include a crewed capability.
More in general, the 2016 "Shared Vision and Goals for the Future of Europe in Space" contained (among others) these goals, which point to uncrewed launch capability only:
- ensure availability and foster the competitiveness and reliability of Ariane, Vega and Soyuz from Europe’s Spaceport;
- ensure that Europe can respond to evolving market demands by developing Ariane 6 and Vega C and their ground infrastructures;
- prepare a future for Europe to better serve institutional and commercial markets by focusing on innovative technologies, investigating future launcher evolutions, demonstrating technical capabilities and preparing routine access to and return from space.
As to why ESA isn't working on a human spaceflight program, I think cost is the main reason. It took years of negotiation among member states to reach agreement on the development of Ariane 6 - a development that's both relatively cheap and aimed at cutting the cost of a launch by 50%. An independent crewed program would be a bigger investment than member countries are willing to make. Participation in the ISS gets ESA most of what they want/need (access to a research lab in space).
Finally, ESA is involved in NASA's crewed spaceflight program: they're building the service module for Orion, based on the ATV.
I can add a little bit more to Hobbes' great answer. ESA cooperates extensively with NASA on a range of projects; the ISS is the biggest, but ESA and NASA are very enmeshed in each other's operations. Almost all of this cooperation is done on a barter basis, where on side provides, say, an instrument, and the other side provides launch, or whatever. The bartering doesn't even have to be within the same project: ESA gets "ISS credit" for some of their contributions to Gateway, for example. With this longstanding system, there's no point to develop an independent human launch capacity when you can instead just focus on the programs you've already developed expertise on, then just barter for the crew slots.