<P><B>Abstract</B></P> <P>The objective of this work was to evaluate the performance of mesophilic continuous anaerobic co-digestion using oil-extracted microalgae (M) and glycerol (G) in co-digestion with chicken litter (CL). The process included the starting up and stabilization of continuous anaerobic bioreactors using CL as a feedstock and the corresponding adaptation to M-CL and M-G-CL feedstocks. The treatments were selected based on a previous report of our research team on Biochemical Methane Potential (BMP) evaluation, taking in consideration only the best M-G-CL feedstock ratios. The performance was evaluated by the Specific Methanogenic Activity (SMA); the best response (270.0 mL CH<SUB>4</SUB> g<SUB>VS added</SUB> <SUP>−1</SUP>) was obtained with a triple co-digestion M-G-CL 30:3:67, which was 39.0% above the CL treatment. These findings have shown that the two main residuals from microalgae biodiesel production (G and M) can be used as a feedstock to improve methane production through anaerobic digestion.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Triple co-digestion with oil-extracted microalgae, glycerol and chicken litter. </LI> <LI> Oil-extracted microalgae and glycerol in co-digestion with chicken litter enhances specific methanogenic activity. </LI> <LI> Maximum methane yield at C:N 6.94 in triple co-digestion. </LI> <LI> Triple co-digestion oil-extracted microalgae:glycerol:chicken litter (30:3:67) enhances methane production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>