No, a quark is not a lepton. Quarks and leptons are two distinct types of elementary particles in the Standard Model of particle physics.
Quarks are fundamental particles that are classified as fermions and are the building blocks of hadrons such as protons and neutrons. Quarks possess fractional electric charges and experience the strong nuclear force. There are six known flavors of quarks: up (u), down (d), charm (c), strange (s), top (t), and bottom (b).
Leptons, on the other hand, are also fermions but have different properties compared to quarks. Leptons do not experience the strong nuclear force and possess integer electric charges. Examples of leptons include electrons, muons, and taus, as well as their associated neutrinos.
So while both quarks and leptons are elementary particles, they have distinct properties and play different roles in the fundamental interactions of particle physics.