  We show the laser-driven acceleration of unprecedented, collimated ($ 2 \
\mathrm{mrad} $ divergence), and quasi-monoenergetic ($ 25 \ \% $ energy
spread) electron beams with energy up to $ 50 \ \mathrm{MeV} $ at $ 1 \
\mathrm{kHz} $ repetition rate. The laser driver is a multi-cycle ($ 15 \
\mathrm{fs} $) $ 1 \ \mathrm{kHz} $ optical parametric chirped pulse
amplification (OPCPA) system, operating at $ 26 \ \mathrm{mJ} $ ($ 1.7 \
\mathrm{TW} $). The scalability of the driver laser technology and the electron
beams reported in this work pave the way towards developing high-brilliance
x-ray sources for medical imaging, innovative devices for brain cancer
treatment, and represent a step towards the realization of a kHz GeV electron
beamline.
