Online graduate programs have grown in number in recent decade and, with it, the acceptability of online degrees. Higher education , however, has been slow to embrace online doctorates for professor positions. Can you get an academic job with a doctorate earned online? It’s possible, but not likely.
 
First consider that academic jobs are few and far between. The academic job market is notoriously grim.

Graduates of traditional brick-and-mortar PhD programs often find it difficult to find jobs in academia. Those of online graduate programs with which hiring committees have little experience face significant challenges.

Second, getting hired in academia entails more than earning the appropriate degree. It requires cultivating a set of experiences and competencies that are to hard get online. Scholarship, publications, and teaching experience are all critical. Do online students have as many opportunities to collaborate with faculty on research outside of their dissertations? Do they develop close and productive relationships with mentors? Do online students have the same opportunities to get teaching experiences as brick-and-mortar students? Supervised teaching experience? It's not impossible to get these experiences in an online setting, but I'd argue that it's a major challenge. Universities are unlikely to hire tenure track instructors who do not have teaching experiences,  publications, or recommendation letters documenting these competencies.

Third, right now academia is a buyer’s market. As an extension of item 1, there’s a glut of PhD holders looking for work. In any such market applicants get weeded out by pedigree. Unfortunately many hiring committees rank online graduate programs at the bottom of the list.

While it is difficult to be hired as a professor in a bricks-and-mortar institution with a graduate degree earned online, it is not impossible. Instead, however, it seems that you would be more likely to be successfully hired at online institutions. You may have an in at such institutions as you know what it like to be a student enrolled in an online graduate program.