Municipal Mayors of San Isidro
| 1 | 1959 | Julian L. Petallo | Teñente del Barrio | |
| 2 | 1959-1964 | Nicarito Laosinguan Tiu | Mayor | Appointed |
| 3 | 1964-1967 | Julian L. Petallo | Mayor | Elected |
| 4 | 1967-1969 | Zosimo Malinao Dulpina | Mayor | Elected |
| 5 | 1969-1972 | Nicarito Laosinguan Tiu | Mayor | Elected |
| 6 | 1972-1980 | Nicarito Laosinguan Tiu | Mayor | Elected |
| 7 | 1980-1986 | Nicarito Laosinguan Tiu | Mayor | Elected |
| 8 | 1986-1987 | Lamberto Bonono Domiños, Sr. | Mayor | Appointed |
| 9 | 1987-1988 | Warlito Malaza | Mayor | Appointed |
| Lolito Golo | DILG | OIC | ||
| 10 | 1988-1992 | Lamberto Bonono Domiños, Sr. | Mayor | Elected |
| 11 | 1992-1995 | Lamberto Bonono Domiños, Sr. | Mayor | Elected |
| 12 | 1995-1998 | Lamberto Bonono Domiños, Sr. | Mayor | Elected |
| 13 | 1998-2001 | Robert Malaza Dulpina | Mayor | Elected |
| 14 | 2001-2004 | Robert Malaza Dulpina | Mayor | Elected |
| 15 | 2004-2007 | Lamberto Bonono Domiños, Sr. | Mayor | Elected |
| 16 | 2007-2010 | Lamberto Bonono Domiños, Sr. | Mayor | Elected |
| 17 | 2010-2013 | Lamberto Bonono Domiños, Sr. | Mayor | Elected |
| 18 | 2013-2016 | Lalaine Espadero Domiños | Mayor | Elected |
| 19 | 2016-2019 | Lamberto E. Dominos, Jr. | Mayor | Elected |