林獻堂一生最重要的文學活動厥為加入櫟社為成員，參與櫟社的活動。日治時代參加詩社者不少人是無法趕上日文世代的一群，在日文無法學、漢文無處切磋、書房又已奉命關閉的情況下，成立詩社，藉著吟詠發抒亡國遺恨、借景敘志，對漢文的保存，詩學之提倡，有其一定的意義。櫟社有幾項特質：1. 注重文化的傳存，不僅另成立《臺灣文學叢誌》提倡文學，且注意傳承，當櫟社成員不斷凋零時，鼓勵舊社員之關係者加入，並給予讀詩、讀書、漢詩習作等訓練；2. 有核心人物來維繫該社，除了文學造詣深的林俊堂、林幼春外，林獻堂、傅錫祺更是維繫成員、辦理詩會的要角；3. 由於林獻堂等的重視史料保存，因此在日治時期能出版詩集及其沿革志的詩社可謂絕無僅有；況且還幫忙林俊堂編成《無悶草堂詩存》，此一工作亦無任何一個詩社能及；4. 櫟社成員雖保持在20多位，但其外圍詩社不少，故對臺灣詩壇影響力不弱。 林獻堂的詩作在櫟社諸子中只能算平平，但對櫟社有諸多貢獻，也是櫟社不可或缺的中心人物。主要在於：首先，只要林獻堂離開臺灣，櫟社的活動必然減少，或者是無；且櫟社聚會常在霧峰召開，與林獻堂有密切關係。第二，櫟社兩次中興，即1941年及1946年，都以林獻堂為主體展開。櫟社得以在皇民奉公會期間繼續發揮效果，實因林獻堂在危急存亡之秋做必要的社員吸收所致。三、林獻堂在財務上也做了支持，如他在1909年加入櫟社後，在翌年櫟社春會開宴時分擔宴會款項。四、基於對歷史的愛好及對資料的重視，林獻堂主張刊行櫟社作品，使櫟社成為資料最完整的詩社。

Joining Li Poetry Society (櫟社) was the most important literature activity in Lin Hsien-t'ang's life. The greater part of the people attended traditional poetry societies during the Japanese colonial period were the generation educated in Chinese. They seldom had the chance to learn Japanese and almost had no place to discuss Chinese literature. In addition, traditional private schools were closed then. Through traditional poetry societies, they could chant to express the sorrow of been colonized and to narrate their principles. These societies contributed much to maintaining the Chinese literature and to promoting traditional Chinese poetry. There are four distinctive features of the Li Poetry Society. At first, it paid much attention to hand down cultural heritage. It published Taiwanese literature collections, encouraged yound men to join and taught them reading and writing Chinese poems. Secondly, there were a few core figures to bind together this poetry society, Lin Hsien-t'ang was one of them. Thirdly, its leader emphasized the importance of preserving historical resources. While other poetry societies never published their own history, the Li Poetry Society published its vicissitudes. Fourthly, the society only kept 20 or more members, but it had many front organizations and had great influence on the circle of poets. Though Lin Hsien-t'ang's poetic works were not outstanding among the poets of the Li Poetry Society, he was undoubtedly the key figure. Every time he left Taiwan for a long duration, the activities of the Li Poetry Society dwindled, or even none. Lin Hsien-t'ang played the leading role in the rejuvenation of the Li Poetry Society in both 1941 and 1946. He recruited new members during the critical time of Kominhokokai (皇民奉公會) period, which kept the Li Poetry Society alive. Aside from this, he offered financial support of the society. Based on the refined tastes of history and culture, he initiated printing the works of the Li Poetry Society, which, in comparison to other societies, preserved most completely works of its members.