Lightweight World/Lineal Champions (135lbs)

Freddie Welsh (7/7/1914 – 28/5/1917)

Welsh beat Willie Ritchie to unify the division
Benny Leonard (28/5/1917 – 15/1/1925)
Leonard retired
Rocky Kansas (7/12/1925 – 3/7/1926)

Kansas beat Jimmy Goodrich to unify the NY/NBA/GB versions of the title
Sammy Mandell (3/7/1926 – 17/7/1930)
Al Singer (17/7/1930 – 14/11/1930)
Tony Canzoneri (14/11/1930 – 23/6/1933)
Barney Ross (23/6/1933 – 15/4/1935)

Ross moved up in weight
Tony Canzoneri (10/5/1935 – 3/9/1936)

Canzoneri (2) beat Lou Ambers (1)
Lou Ambers (3/9/1936 – 17/8/1938)
Henry Armstrong (17/8/1938 – 22/8/1939)
Lou Ambers (22/8/1939 – 10/5/1940)
Lew Jenkins (10/5/1940 – 19/12/1941)
Sammy Angott (19/12/1941 – 14/11/1942)

Angott announced his retirement due to hand problems in November 1942, only to come back in March 1943 and eventually regain the NBA title
Bob Montgomery (21/5/1943 – 19/11/1943)

Montgomery (2) beat Beau Jack (1)
Beau Jack (19/11/1943 – 3/3/1944)
Bob Montgomery (3/3/1944 – 4/8/1947)
Ike Williams (4/8/1947 – 25/5/1951)
Jimmy Carter (25/5/1951 – 14/5/1952)
Lauro Salas (14/5/1952 – 15/10/1952)
Jimmy Carter (15/10/1952 – 5/3/1954)
Paddy DeMarco (5/3/1954 – 17/11/1954)
Jimmy Carter (17/11/1954) – 29/6/1955)
Wallace Bud Smith (29/6/1955 – 24/8/1956)
Joe Brown (24/8/1956 – 21/4/1962)
Carlos Ortiz (21/4/1962 – 10/4/1965)
Ismael Laguna (10/4/1965 – 13/11/1965)
Carlos Ortiz (13/11/1965 – 29/6/1968)
Carlos Teo Cruz (29/6/1968 – 18/2/1969)
Mando Ramos (18/2/1969 – 3/3/1970)
Ismael Laguna (3/3/1970 – 26/9/1970)
Ken Buchanan (26/9/1970 – 26/6/1972)
Roberto Duran (26/6/1972 – 3/2/1979)

Duran moved up in weight
Alexis Arguello (20/6/1981 –15/2/1983)

Arguello (3) beat Jim Watt (1). BNews had Arguello a place above Hilmer Kenty in the ratings
Arguello moved up in weight
Livingstone Bramble (1/6/1984 – 26/9/1986)

Bramble (4) beat Ray Mancini (1)
Edwin Rosario (26/9/1986 – 21/11/1987)
Julio Cesar Chavez (21/11/1987 – 13/5/1989)

Chavez moved up in weight 
Pernell Whitaker (20/8/1989 – 22/5/1992)

Whitaker beat Jose Luis Ramirez to unify the IBF/WBC titles
Whitaker moved up in weight 
Miguel Angel Gonzalez (6/8/1994 – 10/2/1996)

Gonzalez (1) beat Leavander Johnson (4)
Gonzalez moved up in weight
Shane Mosley (2/8/1997 – 31/5/1999)

Mosley (5) beat Philip Holiday (1)
Mosley moved up in weight
Stevie Johnston (14/8/1999 – 17/6/2000)

Johnston (1) beat Angel Manfredy (2)
Jose Luis Castillo (17/6/2000 – 20/4/2002)
Floyd Mayweather Jnr (20/4/2002 – 22/5/2004)

Mayweather moved up in weight
Jose Luis Castillo (5/6/2004 – 7/5/2005)

Castillo (2) defeated Juan Lazcano (1)
Diego Corrales (7/5/2005 – 7/10/2006)
Joel Casamayor (7/10/2006 – 13/9/2008)
Juan Manuel Marquez (13/9/2008 – 14/4/2012)

Marquez moved up in weight
Terence Crawford (29/11/2014 – 24/3/2015)

Crawford (1) beat Fernando Beltran (2)
Crawford moved up in weight
Jorge Linares (24/9/2016 – 12/5/2018)

Linares (1) beat Anthony Crolla (3)
Vasyl Lomachenko (12/5/2018 -