Petras Bartkus, also known by his codenames Žadgaila and Alkupėnas (30 May 1925 – 13 August 1949) was a poet and anti-Soviet Lithuanian partisan.

He studied at the Kaunas higher technic school, and in 1942 he joined the resistance in the Lithuanian Liberty Army.

When the Kęstutis military district was established on 12 September 1946, Bartkus was made the head of its headquarters organizational unit (during which he gained the codename Sąžinė).

On 31 March the Prisikėlimas military district was established and on 1 April Bartkus was selected as its commander[1] (with the codename Mažrimas).

[4][5][1][6] Bartkus died on 13 August 1949 in a fight with MGB agents in the Užpelkiai forest in the Radviliškis district, along with Bronislovas Liesis (another signature of the 1949 declaration), Jonas Vytautas Šniuolis (a member of the LLKS presidium), and two unidentified others.