The incident happened on Monday this week when one of a group of three men is alleged to have attacked a staff member and damaged property at the Queen Street takeaway and drive-thru.
Police said they want to speak to anyone who can help them identify the man in the picture.
A spokesperson for Lincolnshire Police said: “Shortly after 1:30pm on Monday 18th January, a group of three men walked through the drive-through of McDonald’s on Queen Street.
“One of the individuals in the group caused damage to the property and assaulted a member of staff who thankfully sustained no injuries during the incident.
“The suspects then left the scene.
“If you know the identity of the man in the photo or if you witnessed the incident, please contact us.”
Call police on101 quoting incident 20 of 18th January 2021, email [email protected] using incident 20 of 18th January 2021 in the subject line, or anonymously via the independent charity CrimeStoppers on 0800 555 111.