Yes, but only if you consider Theravada realist.
It has often been asserted that Theravada, particularly "classical" Theravada in which the entire Tipitaka and its commentaries are considered authoritative, is ultimately realist. Nevertheless, this criticism, which for the most part comes from Yogacara and Madhyamika, is heavily disputed. For example, in his Introduction to Buddhism, Harvey explains, "'They are dhammas because they uphold their own nature [sabhaava]. They are dhammas because they are upheld by conditions or they are upheld according to their own nature' (Asl.39). Here 'own-nature' would mean characteristic nature, which is not something inherent in a dhamma as a separate ultimate reality, but arise due to the supporting conditions both of other dhammas and previous occurrences of that dhamma. This is of significance as it makes the Mahayana critique of the Sarvastivadin's notion of own-nature largely irrelevant to the Theravada" (87).
Personally, whether or not Harvey is correct in his characterization of the Theravada position, I believe this quasi-realistic view is the result of early Abhidhammikas attempting to reify certain concepts that should never have been reified, e.g. dhammas, khandhas, etc.
In my opinion, the core of texts that constitute the Sutta Pitaka are not realist per se, but there are certain concepts found within Theravada that do appear to present themselves as such. Essentially, I think that classical Theravada, in which the entire Tipitaka and its commentaries are considered authoritative, borders on realism depending on how you understand the terms "dhamma" and "sabhava." All I can say is that Theravada does not go as far as Sarvastivada, although it does push the boundaries and can easily be interpreted as being realist, which then opens the door to accusations of nihilism.
In one of the ways that I like to look at it, the conventional viewpoint explains things through subject, verb and object whereas the ultimate viewpoint explains things through verb alone. In essence, things are being viewed from the perspective of activities and processes. This, I think, is incredibly difficult to see, but perhaps what happens here is that once self-identity view (sakkaya-ditthi) is removed, the duality of subject and object is also removed thereby revealing the level of mere conditional phenomena. Nibbana would then be regarded as the end of this conditional phenomena, or in other words, the cessation of the activity of samsara (perpetual wandering).
This is where one can insert any claims of nihilism if one is able to substantiate that this cessation of activity is the destruction of something real, substantial, etc. In other words, if the five aggregates of clinging (khandhas) are real in the sense that they are concrete, existing entities, conditioned or otherwise, then their cessation would be a type of nihilism. In addition, within classical Theravada, the the goal is said to be the utter extinction of all consciousness per the verse in : "Ettha namanca rupanca, asesam uparujjhati. Vinnanassa nirodhena etthetam uparujjhati" (Here [in nibbana], nama as well as rupa ceases without remainder. By ceasing of consciousness, nama as well as rupa ceases here) (Suan Lu Zaw).
The arguments on both sides become very complex and voluminous at this point. For example, there are arguments that claim that everything is an illusion, i.e., perceived reality is ultimately unreal, hence there is no actual cessation; there are arguments that claim the complete cessation of all consciousness is only nihilistic if one takes consciousness as being "me," "mine," or "myself," etc.
For me, "real" simply means an existing cognizable experience. Going back to my statement concerning how I like to look at this, I understand the five aggregates of clinging to represent things that we do as opposed to just things. In other words, there is an act of intention that goes into our experience. In , for example, the Buddha summarizes stress and suffering (dukkha) as the five aggregates of clinging. Furthermore, in the five aggregates of clinging are described in their verb forms, or in other words, not as things but as activities.
Therefore, when looking at the arising of the five aggregates of clinging in this way, we are effectively looking at the arising of [the activity of] stress and suffering; when looking at the cessation of the five aggregates of clinging in this way, we are effectively looking at the cessation of [the activity of] stress and suffering. Thus, all that ceases is [the activity of] stress and suffering, not an independently existing entity of any kind. Since this cessation is cognizable, it too can be considered "real." Moreover, since only an activity has been stopped, there is no actual destruction of any "thing."
My view is probably not in line with classical Theravada on this point, however, so please consider my thoughts with that caveat in mind.
"Sabbe dhamma nalam abhinivesaya" ().
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