<p>La_0.8-<i>x</i>Eu_<i>x</i>Sr_0.2MnO₃ (LESMO) (<i>x</i> = 0.05, 0.10, 0.15) samples were synthesized by the sol-gel (S-G) method. The effect of Eu³⁺ doping at the A-site on the microstructure, morphological, and magnetocaloric effect (MCE) of LESMO was investigated. XRD revealed that the LESMO samples had a rhombohedral structure within the R-3c space group. The cell volume (<i>V</i>) decreased with increasing Eu³⁺ doping. The magnetic properties of LESMO revealed a ferromagnetic-paramagnetic transition around the Curie temperature (T_C) with an increase in the Eu³⁺ doping level. Using Banerjee’s criterion and utilizing normalization, it was confirmed that a second order magnetic phase transition (SOMPT) occurs in LESMO near T_C. The maximum magnetic entropy change <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10971_2025_6806_Article_IEq1.gif" Format="GIF" Height="21" Rendition="HTML" Resolution="72" Type="Linedraw" Width="78" /> </InlineMediaObject> <EquationSource Format="TEX">\((-\Delta {S}_{M}^{M{ax}})\)</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>(</mo> <mrow> <mo>−</mo> <mi mathvariant="normal">Δ</mi> <msubsup> <mrow> <mi>S</mi> </mrow> <mrow> <mi>M</mi> </mrow> <mrow> <mi>M</mi> <mi>a</mi> <mi>x</mi> </mrow> </msubsup> </mrow> <mo>)</mo> </mrow> </math></EquationSource> </InlineEquation> of LESMO (<i>x</i> = 0.05, 0.10, and 0.15) was 5.22 J/(kg·K), 4.68 J/(kg·K), and 3.55 J/(kg·K), respectively, under an external magnetic field (H). The relative cooling power (<i>RCP</i>) of LESMO was 285.01 J·kg⁻¹ (<i>x</i> = 0.05), 289.60 J·kg⁻¹ (<i>x</i> = 0.10), and 300.15 J·kg⁻¹ (<i>x</i> = 0.15). La_0.65Eu_0.15Sr_0.2MnO₃ exhibits a higher maximum <i>RCP</i> of 300.15 J·kg⁻¹, equal to 73.2% of that of Gd.</p> Graphical Abstract <p></p>