Determinations of lithium abundance are given for sixty-nine early F field stars and six stars in the Pleiades Cluster. They were calculated from estimated equivalent widths and predicted line strengths, denved from a grid of model atmospheres. A wide range of Li content was found in the field stars, the maximum abundance exceeding the solar value by a factor of more than 50. Although the correlation of Li abundance with estimated age is poor, there is a tendency for some of the youngest stars to have the highest Li content. In the Pleiades Cluster, the average Li content of the G and F stars is similar. This is not true in the Hyades Cluster where, at type G5, there is a distinct drop in the Li content, which may be interpreted as caused by convective depletion. The time scale for depletion in G stars must then lie between the ages of the Pleiades and the Hyades. There is a real variation from star to star in the Li content of the Pleiades F stars that is similar to that found in the Hyades. If it is caused by convective depletion, then some stars must have a depletion time scale less than the age of the Pleiades. The differences are possibly regulated by the secondary effects of rotation or some other circulation mechanism operating in F stars. On the other hand, they may reflect differences in the initial Li content.