During the latest tour of duty, members of the Prince of Wales's Company worked closely with Afghan security forces in Nahr-e-Saraj District to suppress insurgents and help the Afghan troops to take the lead themselves.
The battalion lost three members during the tour including Carmarthen-born Lance Corporal Lee Davies, 27, who grew up in Cardigan.
Lance Corporal Davies died after being hit by small arms fire while on working as part of a police advisory team in the Lashkar Gah district of Helmand province in May last year.
Major Ed Launders, Prince of Wales's Company Commander, said: "The tour in Afghanistan was extremely tough, but made much easier through the abundant support of the people of Wales which carried us through.
"It is a tremendous honour and privilege to march through Carmarthen and to display our gratitude."
1st Battalion Welsh Guards will parade through Carmarthen town centre today, after a six month tour in Afghanistan.
Starting at 12pm the Prince of Wales' Company will march from the town's TA centre, through Picton Terrace and Lammas Street towards the Guild Hall.
The Mayor of Carmarthen will take the salute and inspect the troops, before the parade makes its way back to the TA Centre along Queen Street, Spilman Street and King Street, for a reception.