  We show that there exists a quantum compact metric space which underlies the
setting of each Sobolev algebra associated to a subelliptic Laplacian
$\Delta=-(X_1^2+\cdots+X_m^2)$ on a compact connected Lie group $G$ if $p$ is
large enough, more precisely under the (sharp) condition $p > \frac{d}{\alpha}$
where $d$ is the local dimension of $(G,X)$ and where $0 < \alpha \leq 1$. We
also provide locally compact variants of this result and generalizations for
real second order subelliptic operators. We also introduce a compact spectral
triple (=noncommutative manifold) canonically associated to each subelliptic
Laplacian on a compact group. In addition, we show that its spectral dimension
is equal to the local dimension of $(G,X)$. Finally, we prove that the Connes
spectral pseudo-metric allows us to recover the Carnot-Carath\'eodory distance.
