  This thesis can be divided into several parts. The first one consists in a
detailed historical review of quarkonium physics, centered on the different
production models successively introduced. Then comes a review of the currently
available data on high-energy hadronic production of J/psi, psi' and Upsilon's.
In a third part, we concentrate on the extension of the Colour-Singlet Model
beyond the static approximation. In this extension, we emphasise that a simple
generalisation of the static case is not sufficient and new 4-point vertices
are to be introduced to restore gauge invariance. Since these new vertices are
not fully constrained, we propose a method to study this freedom. Finally, we
apply our approach to the production at the Tevatron and RHIC, where we show
that a combination of our contributions with fragmentation within the
Colour-Octet Mechanism is able to reproduce the measurements both for cross
sections and for polarisation.
