We present a diode-pumped Yb:YLF laser system generating 100-mJ sub-ps pulses at a 1-kHz repetition rate (100 W average power) by chirped-pulse amplification. The laser consists of a cryogenically cooled 78 K, regenerative, eight-pass booster amplifier seeded by an all-fiber front end. The output pulses are compressed to 980 fs in a single-grating Treacy compressor with a throughput of 89%. The laser will be applied to multi-cycle THz generation and pumping of high average power parametric amplifiers.