Olefin cross metathesis was used to efficiently functionalize polyolefin dendrimers, polymers, and gold nanoparticles using the second-generation Grubbs catalyst. In these structures, the tethers were lengthened to prevent the facile cross metathesis that otherwise predominates in polyolefin dendrimers having short tethers. This synthetic strategy allows the one-step access to polyacid, polyester, and polyferrocenyl structures from polyolefins. Cross metathesis is also used to efficiently achieve an iterative divergent dendritic construction. All the cross metathesis reactions were monitored by 1H NMR showing the chemo-, regio-, and stereoselectivity. MALDI-TOF mass spectrometry was a very useful technique to confirm the efficiency of this synthetic strategy.