All Ceylon Tamil Congress, the oldest Tamil political party in Sri Lanka. ACTC was founed in 1944 by G.G. Ponnambalam. Due to the cooperation of ACTC with United National Party a group led by S.J.V. Chelvanayakam broke away in 1949 forming the Federal Party .
ACTC was largely discredited when their ally UNP moved away from bilingual and bicommunal policies towards a pro-Sinhala stance. Thus FP emerged as the major Tamil party in 1956.
In 1972 ACTC and FP formed the Tamil United Front, which later evolved into the Tamil United Liberation Front.
Ahead of the 2001 elections, ACTC joined the LTTE-backed Tamil National Alliance. In the 2004 elections TNA contested as Illankai Tamil Arasu Kachchi .
In Tamil ACTC is called அகில இலங்கைத் தமிழ்க் காங்கிரஸ்.
