Where is Cron Crontab jobs log file Located in Ubuntu Linux

If you are trying to locate the cron crontab jobs log file on your Ubuntu Linux distribution OS, you should find it under /var/log/syslog.

You can simply make use of the cat, head or tail command to view the logs,

# cat  /var/log/syslog

Jul 16 09:30:01 ubuntu CRON[1234]: (root) CMD
Jul 16 09:45:01 ubuntu CRON[5678]: (user) CMD 
Jul 16 10:00:00 ubuntu kernel: Booting Linux on physical CPU 0x0
Jul 16 10:15:23 ubuntu NetworkManager[123]:  Activation (eth0) successful
Jul 16 10:30:45 ubuntu apt: Installed python3
Jul 16 11:45:10 ubuntu sshd[9876]: Accepted publickey for user from 192.168.0.100 port 12345 ssh2
Jul 16 12:00:05 ubuntu systemd[1]: Stopped target Timers.
Jul 16 12:15:20 ubuntu kernel: EXT4-fs warning (device sda1): running out of free inodes
Jul 16 12:30:35 ubuntu kernel: eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
Jul 16 12:45:50 ubuntu apache2[5432]: [info] [client 192.168.0.200] Request received for URL /code2care/v1/data/