Bellmanseken, Historic oak tree in Stockholm Municipality, Sweden

Bellmanseken is an oak standing on high ground outside the western facade of the Hasselbacken restaurant on Södra Djurgården. Its crown was heavily pruned around 1890, when almost all branches were sawn off; the trunk's hollow was later filled with cement and stone and stabilized with several iron bands. In 1969 Gunnar Brusewitz described it as a "bedrövlig spillra" (wretched splinter), yet the tree still stands.

The oak stands by the former site of Dunderhyttan, the lively predecessor of Hasselbacken, where Carl Michael Bellman and Gustav III, the latter incognito, gathered. Tradition holds that Bellman carved his name into the bark, but an English autograph hunter removed it, after which the tree began to rot from within. In 1872 the Bellman statue by Alfred Nyström was cast in zinc nearby and the oak was nearly felled to make room. Around 1890 the crown withered and almost all branches were sawn off; the trunk was later filled with cement and stone and bound with iron bands.

The oak is named after Carl Michael Bellman, who according to tradition sat beneath it improvising songs to the mandolin; Fredmans epistel 25 is said to have been written here. Par Bricole first held its annual Bellman Day celebration, on 26 June, at this tree. Tradition also holds that Bellman carved his name into the bark, a signature later removed by an autograph hunter from England.

The oak stands by the western facade of the Hasselbacken restaurant on Södra Djurgården, a short walk from the Djurgården tram and bus stops. The ground around the trunk is uneven and the tree is fenced off, so it is best viewed from the nearby path.

According to an 1865 article in Illustrerad Tidning, Bellman carved his name into the bark; an autograph hunter from England later removed the signature, after which the oak began to rot from within. Around 1890 the crown withered and almost all branches were sawn off; botanist Rutger Sernander called the intervention ruthless in his 1926 book Stockholms natur. The trunk cavity was later filled with cement and stone and held together with iron bands.