Sebastian Smolira, 15, from the Greenock area, has not been seen since about 1.30 pm on October 15.
Officers are appealing for the public’s assistance in tracing the young boy.
Sign up to our daily newsletter
The i newsletter cut through the noise
He is 5ft7in, has short brown hair and is slim, with a fair complexion.
Sebastian Smolira, aged 15, is missing from the Greenock area picture: Police Scotland
At the time he went missing, Sebastian was dressed all in black and wearing a black facemask.
A police spokesman said: “Anyone with information as to the whereabouts of Sebastian is asked to contact the Police by calling 101 quoting incident number 3868 of 15 October 2020.”
A message from the Editor:
Thank you for reading this story on our website. While I have your attention, I also have an important request to make of you.
The dramatic events of 2020 are having a major impact on many of our advertisers - and consequently the revenue we receive. We are now more reliant than ever on you taking out a digital subscription to support our journalism.