Lorenzo "Ka Tanny" Martinez Tañada Sr., PLH, (born Lorenzo Tañada y Martinez, August 10, 1898 – May 28, 1992) was a Filipino nationalist lawyer, senator, and human and civil rights activist best known for his staunch opposition to martial law under Ferdinand Marcos and to the continued presence of US military bases in the Philippines.
Serving in the Philippine Senate for 24 years beginning in 1947, he was the longest-serving senator in Philippine history and is referred to as the "grand old man of Philippine politics."In his youth, he was also a national football team goalkeeper and was part of the Philippine national team that bagged silver medals at the 1923 and 1925.He was the father of Philippine Senator Wigberto Tañada and the grandfather of Congressman Erin Tañada.