This study presents a modified silica gel used as the solid support that an adsorbent modified by pillar[5]arene as a new and efficient absorbent (Si-APTMS-pillar[5]arene) was used for the removal of Cu(II) ions from aqueous solution. XRD, FT-IR, and SEM analysis were used to characterize the morphology and structure of the Si-APTMS-pillar[5]arene adsorbent material. The maximum adsorption capacities of Cu(II) ions at dissimilar temperatures via the Langmuir model were 75.1880 mg/g (298 K), 76.3359 mg/g (308 K), 78.1250 mg/g (318 K), and 79.3651 mg/g (328 K), respectively, at 90 min and pH 5.0. The selectivity to Cu(II) ions is quite high, and especially the prepared adsorbent showed high reusability and maintained its high efficiency even after 3–5 cycles of regeneration. Si-APTMS-pillar[5]arene adsorbent prepared for the effective treatment of water and copper-contaminated wastewater is promising as a new, cost-effective, and non-toxic adsorption technique.