The reaction of 4‐chloro‐1,2‐dimethyl‐4‐supersilylsila‐1‐cyclopentene (2 a) with Li[NiPr2] at −78 °C results in the formation of the formal 1,4‐addition product of the silacyclopentadiene derivative 3,4‐dimethyl‐1‐supersilylsila‐1,3‐cyclopentadiene (4 a) with 2,3‐dimethyl‐4‐supersilylsila‐1,3‐cyclopentadiene (5 a). In addition the respective adducts of the Diels–Alder reactions of 4 a+4 a and 4 a+5 a were obtained. Compound 4 a, which displays an s‐cis‐silacyclopentadiene configuration, reacts with cyclohexene to form the racemate of the [4+2] cycloadduct of 4 a and cyclohexene (9). In the reaction between 4 a and 2,3‐dimethylbutadiene, however, 4 a acted as silene as well as silacyclopentadiene to yield the [2+4] and [4+2] cycloadducts 10 and 11, respectively. The constitutions of 9, 10, and 11 were confirmed by NMR spectroscopy and their crystal structures were determined. Reaction of 4‐chloro‐1,2‐dimethyl‐4‐tert‐butyl‐4‐silacyclopent‐1‐ene (2 c) with KC8 yielded the corresponding disilane (12), which was characterized by X‐ray crystal structure analysis (triclinic, P$\bar 1$). DFT calculations are used to unveil the mechanistic scenario underlying the observed reactivity.