There are two terminals at Kuala Lumpur, KLIA and klia2. Both have the same airport code (KUL), so the terminal you are at depends on the airline you are flying. Here’s a list of airlines flying from each terminal:
Also at KLIA
Air Astana (KC)
Air Mauritius (MK)
All Nippon Airways (NH)
Bangkok Airways (PG)
Biman Bangladesh Airlines (BG)
British Airways (BA)
China Airlines (CI)
China Eastern Airlines (MU)
China Southern Airlines (CZ)
Condor (DE)
Ethiopian Airlines (ET)
EVA Air (BR)
Flynas (XY)
Himalaya Airlines (H9)
Iraqi Airways (IA)
Japan Airlines (JL)
KLM (KL)
Korean Air (KE)
Lucky Air (8L)
Mahan Air (W5)
Nepal Airlines (RA)
Oman Air (WY)
Pakistan International Airlines (PK)
Philippine Airlines (PR)
Regent Airways (RX)
Royal Brunei Airlines (BI)
Royal Jordanian (RJ)
Saudia (SV)
Shenzhen Airlines (ZH)
SilkAir (MI)
SriLankan Airlines (UL)
Thai Smile (WE)
Turkish Airlines (TK)
US-Bangla Airlines (BS)
Uzbekistan Airways (HY)
VietJet Air (VJ)
Vietnam Airlines (VN)
XiamenAir (MF)