Población Illescas
| Año | Población |
|---|---|
| 2023 | 31327 |
| 2022 | 30553 |
| 2021 | 30229 |
| 2020 | 29558 |
| 2019 | 28894 |
| 2018 | 28064 |
| 2017 | 27332 |
| 2016 | 26672 |
| 2015 | 25964 |
| 2014 | 25721 |
| 2013 | 25382 |
| 2012 | 24581 |
| 2011 | 23627 |
| 2010 | 22482 |
| 2009 | 21264 |
| 2008 | 19167 |
| 2007 | 17312 |
| 2006 | 15830 |
| 2005 | 14771 |
| 2004 | 13692 |
| 2003 | 12704 |
| 2002 | 11736 |
| 2001 | 10940 |
| 2000 | 10347 |
| 1999 | 10106 |
| 1998 | 9930 |
| 1996 | 9743 |