If you mean to build yourself, yes, there are several.

A few examples...

https://rosco-m68k.com/

https://github.com/74hc595/68k-nano

https://shop.mcjohn.it/en/diy-kit/46-68k-mbc.html

https://www.kswichit.com/68k/68k.html

This one is a one-off but for me it is one of the most impressive:

https://www.ist-schlau.de/

It runs EmuTOS and 68K Enhanced BASIC.

If your question was for a machine to run Atari System V Unix on, though, I'm afraid the answer is: an Atari TT. None of the m68k machines (or FPGA emulations thereof) mentioned in the other comments will run it.

Perhaps (but I didn't test) Atari System V Unix would run under the Hatari emulator.

The Firebee (http://firebee.org/) is ColdFire based, and ColdFire is pretty much m68k cleaned up for the new millennium and pretty much backwards compatible (some opcodes are different but can be translated in software, or things can be re-assembled without huge modifications.)

I'm not sure of the state of the Linux port for it, but it runs Atari TOS and EmuTOS (a GPL rewrite) and the FreeMiNT extensions which turn TOS into a multitasking POSIX compliant system that runs most GNU-type utilities.

MiSTer Project does 68000 on an NE10 FPGA.

This one is ready made: http://www.apollo-core.com/v4.html