In Swansea, the party added one seat to hold 48 out of 72 seats, while Plaid Cymru made inroads picking up seven new seats in neighbouring NPT.
Pembrokeshire remains in the hands of independents, while Carmarthenshire has no party in overall control.
Swansea council leader Rob Stewart said Labour's success in the city was because it had offered hope.
"We came into this election on a very positive manifesto, offering people hope, aspiration, a better city, a better life," he said.
"We'd just delivered the City Deal for Swansea, the city centre is being rejuvenated, we're after the Tidal Lagoon - we're hoping to land that very shortly, and we're bidding to be the city of culture in 2021.
"We've demonstrated we can deliver for the people of Swansea and we're standing on an even more ambitious programme for the next five years."
In Swansea, independents took nine seats, Conservatives eight and Liberal Democrats seven.
Meanwhile in Neath Port Talbot, Plaid Cymru made inroads picking up seven new seats.
In Pembrokeshire, former deputy council leader Rob Lewis lost his seat in Martletwy to Di Clements of the Conservatives.
Independent candidates won 34 seats in the county, Conservative had 12, Labour seven, Plaid Cymru six and the Lib Democrats gained just one.
In Carmarthenshire, Plaid Cymru won the most seats with 36, while Labour gained 22 and the independents 16.
Labour has increased its majority in Swansea and held on to control of Neath Port Talbot council.