The planet with the least eccentric orbit in our solar system is Venus.

Here's why:

* Eccentricity measures how much an orbit deviates from a perfect circle. A value of 0 represents a perfect circle, while a value closer to 1 indicates a more elongated, elliptical orbit.

* Venus has an eccentricity of 0.0068, which is incredibly close to zero. This means its orbit is almost perfectly circular.

While other planets like Neptune and Uranus also have relatively low eccentricities, Venus's orbit is the most circular of all.