Owens Road Services has won a two year contract with Amazon, delivering loads between fulfilment centres.
Since February, the Welsh operator has been transporting goods between Amazon's Swansea site to locations across the UK, excluding Scotland.
The online retail giant awarded the contract on the basis that Owens is local to Amazon's Swansea operation and has national reach.
Owens business development manager Barry Evans said: "We are pleased to be working with Amazon across the UK and are looking forward to building and sustaining partnership over the coming years."
Last month Owens revealed that it had returned back to profit after three consective years of losses.