Llanelly Borough Council was a local authority created in 1913 when the existing Urban District Council achieved borough status. The Council consisted of 24 members, eighteen of whom were elected councillors and the remaining six were aldermen. The councillors were elected on a triennial cycle, with a third of councillors retiring each year. Aldermen were elected for a six-year term from within the council membership. It was renamed Llanelli Borough Council in the 1960s.
1945 Llanelly Borough Council election.
At the first post-war election, eight seats were contested, as six councillors retired with two vacancies to be filled. In addition, the term of three aldermen elected in 1935 came to an end, although H.W. Bowen (Lab) had recently died and Daniel Roberts (Ind) decided not to stand.
Labour candidates won a sweeping victory, taking seven of the eight seats and gaining a majority on the borough council for the first time. Three Independents co-opted to fill vacancies during the war years were defeated, as was Alderman W.E. Davies in Ward Two. 
By-elections.
At the statutory meeting, Dr H.D. Llewellyn (Ind), Douglas Hughes (Lab) and John Griffiths (Lab) were elected aldermen. This led to considerable criticism over the alleged reaction of the seniority principles which had previously been unofficially adopted when selecting aldermen 
At the by-elections which followed, much press attention focused on the decision of the British Legion to run candidates, after they were challenged to do so at a council meeting by Labour members. While the contest was close in Ward One, Labour nevertheless took all three seats, thus consolidating their majority.
1946 Llanelly Borough Council election.
All three wards were contested by two Independent, two Labour and two Communist candidates. The Independents gained four seats; three at the expense of Labour and the fourth by ousting the sole remaining Communist counicllor. Defeated Labour candidates included sitting county councillor David Richards.
1947 Llanelly Borough Council election.
Labour captured all six seats, with two former mayors among the defeated Independent candidates. Llanelli was reported to be the only borough in the United Kingdom where Labour gained control.
1949 Llanelly Borough Council election.
Following a decision to move the municipal election from the autumn to the spring throughout England and Wales, the scheduled 1948 elections were postponed. For the first time, no Independent candidates were nominated in two of the wards, resulting in an unopposed return in Ward Three. Three Independent aldermen stood down but they all decided not to seek re-election. In addition, Reginald John B.Sc., headmaster of Lakefield School, stood down as a Labour councillor on health grounds. 
The election resulted in one Independent gain, as Henry Richards, unsuccessful at a recent County by-election, gained a seat in Ward One. 
By-elections.
At the statutory meeting on 23 May, Labour councillors D.L. Richards, Daniel Rees and Gwilym Thomas were elected aldermen. 
At the by-elections, Labour won all three seats leaving the party with eighteen members on the borough council as opposed to six Independents.
1950 Llanelly Borough Council election.
While four of the retiring members were Independents, Labour gained a seat. 
1951 Llanelly Borough Council election.
Labour defended all six seats but lost one to the Independents.