Yes, according to Google’s official documents cited below, internal linking is a ranking factor:

“We’ve combined the signals we use for sitelinks generation and ranking — like the link structure of your site — with our more traditional ranking system, creating a better, unified algorithm. From a ranking perspective, there’s really no separation between “regular” results and sitelinks anymore” – source

“Other factors can include how a site is structured, whether the words of a user’s query appear in the title, how close the words are on the page, and so on” – source